Engineers said in February that corrosion of the metal cables supporting the Genoa highway bridge had reduced the bridge's strength by 20 per cent – months before the structure's deadly collapse last week, reports said.

Despite the findings, the Italian magazine Espresso wrote that "neither the ministry, nor the highway company, ever considered it necessary to limit traffic, divert heavy trucks, reduce the roadway from two to one lanes or reduce the speed" of vehicles on the key artery for the northern port city.

A large section of the Morandi Bridge collapsed on 14 August during a heavy downpour, killing 43 people and forcing the evacuation of more than 600 others living in apartment buildings beneath another section of the bridge.

Prosecutors are focusing their investigation into the cause of the bridge's collapse on possible faulty maintenance or design flaws.

After workers heard creaking noises coming from the part of the bridge that was still standing, firefighters suspended an operation to allow evacuated residents to retrieve their belongings from apartments under the bridge.

The Italian news agency ANSA reported that officials have ruled out that the sound could be caused by wind, and that more checks are under way.

Work is continuing to clear tonnes of bridge debris that cascaded onto a dry riverbed below.

Espresso cited the minutes of a meeting of the Genoa public works superintendent, which included Roberto Ferrazza, an architect named to head a government commission looking into the disaster, and Antonio Brencich, an engineer who has been outspoken about the bridge's flaws.

Former transport minister Graziano Delrio told a news conference that "no one ever signalled the necessity of limiting traffic" on the bridge.

Espresso reporter Fabrizio Gatti said a reduction of 20 per cent strength would not be significant in a modern bridge, but on a structure with the known defects of the Morandi Bridge it should have merited swifter, more decisive action.

Mr Gatti said: "Everyone was well aware of the situation on that bridge."

Italian bridge collapses: part of highway gives way in Genoa Show all 50 1 /50 Italian bridge collapses: part of highway gives way in Genoa Italian bridge collapses: part of highway gives way in Genoa Morandi bridge after it collapsed, in Genoa EPA Italian bridge collapses: part of highway gives way in Genoa A satellite image of the collapsed section of the Morandi Bridge EPA/European Space Imaging Italian bridge collapses: part of highway gives way in Genoa Rescuers inspect the rubble and wreckages AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa Night view of the Morandi bridge collapsed in Genoa EPA Italian bridge collapses: part of highway gives way in Genoa Displaced people from their homes EPA Italian bridge collapses: part of highway gives way in Genoa Rescuers work among the rubble AP Italian bridge collapses: part of highway gives way in Genoa Rescuers inspect the rubble and wreckages AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa A rescuer look over towards part of the Morandi motorway bridge three days after a section collapsed in the northwestern city Genoa on August 16, 2018. - Italy's populist government was on a war footing with the Italian operator of the bridge that collapsed and killed dozens in the port city of Genoa as desperate efforts to find survivors in the rubble went into a third day. (Photo by Piero CRICIATTI / Piero CRUCIATTI / AFP / AFP)PIERO CRICIATTI/AFP/Getty Images PIERO CRICIATTI AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa A satellite image of the collapsed section of the Morandi Bridge EPA/European Space Imaging Italian bridge collapses: part of highway gives way in Genoa People living in the buildings in the area have been evacuated EPA Italian bridge collapses: part of highway gives way in Genoa Excavators dig into the rubble at the site of the highway-bridge-collapse disaster EPA Italian bridge collapses: part of highway gives way in Genoa epa06952160 Night view of the Morandi bridge collapsed in Genoa, Italy, 15 August 2018 (issued on 16 August 2018). People living in the buildings in the area have been evacuated following the collapse of a section of the Morandi bridge because there is a risk the other parts of the bridge could fall. The death toll for Tuesday's highway-bridge-collapse disaster has risen to 39, according to reports on 15 August, and the Italian Government proclaimed national mourning for the Genoa tragedy. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa A lorry stands on the edge AFP/Getty Italian bridge collapses: part of highway gives way in Genoa epa06951240 Displaced people from their homes in the area of he highway-bridge-collapse disaster in Genoa, Italy, 15 August 2018. People living in the buildings in the area have been evacuated following the collapse of a section of the Morandi bridge because there is a risk the other parts of the bridge could fall. The death toll for Tuesday's highway-bridge-collapse disaster has risen to 39, according to reports on 15 August, and the Italian Government will proclaim national mourning for the Genoa tragedy. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa A general view shows apartment buildings under the Morandi motorway bridge in background one day after a section collapsed in Genoa on August 15, 2018. - Nearly 40 people died on August 14, 2018 when a giant motorway bridge collapsed in Genoa in northwestern Italy, with the death toll expected to mount further. (Photo by Piero CRUCIATTI / AFP)PIERO CRUCIATTI/AFP/Getty Images PIERO CRUCIATTI AFP/Getty Italian bridge collapses: part of highway gives way in Genoa A large section of the Morandi viaduct, of which the A10 motorway runs, collapsed in Genoa Reuters Italian bridge collapses: part of highway gives way in Genoa The collapsed Morandi Bridge is seen in the Italian port city of Genoa August 14, 2018. REUTERS/Stringer NO RESALES. NO ARCHIVES. STRINGER Reuters Italian bridge collapses: part of highway gives way in Genoa Rescuers at work amid the rubble EPA Italian bridge collapses: part of highway gives way in Genoa The collapsed Morandi Bridge is seen in the Italian port city of Genoa, Italy August 14, 2018. REUTERS/Stefano Rellandini STEFANO RELLANDINI Reuters Italian bridge collapses: part of highway gives way in Genoa A large section of the Morandi viaduct, of which the A10 motorway runs, collapsed in Genoa AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa A picture taken on August 14, 2018 shows vehicles standing on a part of a giant motorway bridge after a section collapsed earlier in Genoa. - At least 22 people were killed on August 14 when the giant motorway bridge collapsed, with several more feared dead in what Italy's transport minister described as an "immense tragedy". The collapse, which saw a vast stretch of the A10 freeway tumble on to railway lines in the northern port city, was the deadliest bridge failure in Italy for years, and the country's deputy transport minister warned the death toll could climb further. (Photo by ANDREA LEONI / AFP)ANDREA LEONI/AFP/Getty Images ANDREA LEONI AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa An injured man talks to reporters as he leave the site where the Morandi highway bridge collapsed in Genoa, northern Italy, Tuesday, Aug. 14, 2018. A large section of the bridge collapsed over an industrial area in the Italian city of Genova during a sudden and violent storm, leaving vehicles crushed in rubble below. (AP Photo/Alexander Zemlianichenko) Alexander Zemlianichenko AP Italian bridge collapses: part of highway gives way in Genoa A destroyed truck is pictured as rescuers are at work amid rubble and wreckage after a section of a giant motorway bridge collapsed earlier in Genoa on August 14, 2018. - At least 22 people were killed on August 14 when the giant motorway bridge collapsed, with several more feared dead in what Italy's transport minister described as an "immense tragedy". The collapse, which saw a vast stretch of the A10 freeway tumble on to railway lines in the northern port city, was the deadliest bridge failure in Italy for years, and the country's deputy transport minister warned the death toll could climb further. (Photo by ANDREA LEONI / AFP)ANDREA LEONI/AFP/Getty Images ANDREA LEONI AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa Rescue workers at the collapsed Morandi Bridge Reuters Italian bridge collapses: part of highway gives way in Genoa Rescuers are at work amid the rubble of a section of a giant motorway bridge that collapsed earlier, on August 14, 2018 in Genoa. - Rescuers scouring through the wreckage after part of a viaduct of the A10 freeway collapsed said there were "tens of victims", while images from the scene showed an entire carriageway plunged on to railway lines below. (Photo by ANDREA LEONI / AFP)ANDREA LEONI/AFP/Getty Images ANDREA LEONI AFP/Getty Italian bridge collapses: part of highway gives way in Genoa Cars seen among the rubble Vigili Del Fuoco/AP Italian bridge collapses: part of highway gives way in Genoa epa06948876 Rescuers at the site of the collapsed bridge in Genoa, Italy, 14 August 2018. A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa on Tuesday. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa TOPSHOT - A picture taken on August 14, 2018 in Genoa shows a section of a giant motorway bridge that collapsed earlier injuring several people. - Rescuers scouring through the wreckage after part of a viaduct of the A10 freeway collapsed said there were "tens of victims", while images from the scene showed an entire carriageway plunged on to railway lines below. (Photo by Andrea LEONI / AFP)ANDREA LEONI/AFP/Getty Images ANDREA LEONI AFP/Getty Italian bridge collapses: part of highway gives way in Genoa epa06948886 Rescuers at work amid the rubble after a highway bridge collapsed in Genoa, Italy, 14 August 2018. A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa on Tuesday. Several people have died, rescue sources said. Several vehicles were crushed under the rubble with dead people inside, the sources said. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa This handout picture provided by the Italian police (Polizia di Stato) on August 14, 2018 shows a collapsed section of a viaduct on the A10 motorway in Genoa. - A section of a viaduct on the A10 motorway collapsed on August 14, 2018 in Genoa, Italian firefighters said, with cars and trucks trapped among the rubble. Television images showed the viaduct in the mist with a huge chunk missing, with Italian media reporting that 200 metres of the "Morandi" bridge had fallen away. (Photo by Handout / ITALIAN POLICE / AFP) / RESTRICTED TO EDITORIAL USE MANDATORY CREDIT Â« AFP PHOTO / HO / POLIZIA DI STATO Â» - NO MARKETING NO ADVERTISING CAMPAIGNS DISTRIBUTED AS A SERVICE TO CLIENTSHANDOUT/AFP/Getty Images HANDOUT AFP/Getty Italian bridge collapses: part of highway gives way in Genoa A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy EPA Italian bridge collapses: part of highway gives way in Genoa Rescuers work among the debris of the collapsed Morandi highway bridge AP Italian bridge collapses: part of highway gives way in Genoa The viaduct gave way amid torrential rain EPA Italian bridge collapses: part of highway gives way in Genoa The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river AP Italian bridge collapses: part of highway gives way in Genoa Around 10 vehicles are involved in the collapse, rescue sources said EPA Italian bridge collapses: part of highway gives way in Genoa A view of the collapsed Morandi highway bridge ANSA via AP Italian bridge collapses: part of highway gives way in Genoa Rescue teams on the site EPA/Italian Firefighters Italian bridge collapses: part of highway gives way in Genoa epa06948834 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa epa06948839 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa epa06948835 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa Rescuers at the site of the collapsed bridge EPA Italian bridge collapses: part of highway gives way in Genoa epa06948817 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa Both sides of the highway fell AFP/Getty Images Italian bridge collapses: part of highway gives way in Genoa epa06948809 A handout photo made available by Italian firefighters shows rescue teams on the site of a collapsed bridge over the A10 highway in Genoa, Italy, 14 August 2018. A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa on Tuesday. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said. The viaduct gave way amid torrential rain. EPA/ITALIAN FIREFIGHTERS HANDOUT TO BE USED SOLELY TO ILLUSTRATE NEWS REPORTING OR COMMENTARY ON THE FACTS OR EVENTS DEPICTED IN THIS IMAGE; NO ARCHIVING; NO LICENSING +++ HANDOUT EDITORIAL USE ONLY/NO SALES ITALIAN FIREFIGHTERS HANDOUT EPA/Italian Firefighters Italian bridge collapses: part of highway gives way in Genoa The site of a collapsed bridge EPA/Italian Firefighters Italian bridge collapses: part of highway gives way in Genoa https://twitter.com/BattelliSergio/status/1029306695586066433?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1029306695586066433&ref_url=https%3A%2F%2Fwww.bbc.com%2Fnews%2Fworld-europe-45183624 Sergio Battelli/Twitter Italian bridge collapses: part of highway gives way in Genoa Rescue teams on the site EPA/Italian Firefighters Italian bridge collapses: part of highway gives way in Genoa epa06948816 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa epa06948815 A large section of the Morandi viaduct upon which the A10 motorway runs collapsed in Genoa, Italy, 14 August 2018. Both sides of the highway fell. Around 10 vehicles are involved in the collapse, rescue sources said Tuesday. The viaduct gave way amid torrential rain. The viaduct runs over shopping centres, factories, some homes, the Genoa-Milan railway line and the Polcevera river. EPA/LUCA ZENNARO LUCA ZENNARO EPA Italian bridge collapses: part of highway gives way in Genoa Italy, Genoa - bridge collapse https://twitter.com/emergenzavvf/status/1029312140652564481 Vigili del Fuoco/Twitter

Bidding on a 20 million euro (£17.9 million) contract to reinforce two of the major supports for the bridge, including one that collapsed, was scheduled to close next month.

The Italian government, meanwhile, appeared divided on how to proceed in relation to Autostrade per l'Italia, the company that operated the section of highway that collapsed.

Transport and infrastructure minister Danilo Toninelli was quoted by the Milan daily Corriere della Sera as saying that he supported the nationalisation of Italy's toll highways.

"Think of all the revenues that would return to the government through tolls, to use not to donate to shareholders' dividends but to reinforce the quality of service and security on our roadways," Mr Toninelli was quoted as saying.

Deputy premier Matteo Salvini told reporters he remains in favour of public-private cooperation in infrastructure.

Premier Giuseppe Conte said procedures have begun to revoke Autostrade per l'Italia's concession to operate some 1,900 miles of Italian highways, about half of the total major routes operated by private companies.

Italy's main union confederation estimates it would cost Italy between 15 billion and 18 billion euros (£13.45 billion to £18.4 billion) to revoke the highway rights.

The company which owns Autostrade, Atlantia, lost 9.5 per cent in its shares to 17.50 euro in trading, after a late opening due to volatility.

It shed 22 per cent last Thursday, the first trading day after the government announced its intentions, before returning to positive gains on Friday.