Daley Thompson has labelled the corruption scandal surrounding international athletics as the worst crisis to have ever hit the sport - and worse than that at FIFA.

French police have announced an investigation into former IAAF president Lamine Diack, who is suspected of receiving 1million euros to cover up doping offences by Russian athletes, with other IAAF officials allegedly involved.

Officers visited the headquarters of international athletics in Monaco on Tuesday and took documents, a statement from the IAAF confirmed.

Daley Thompson says the corruption scandal surrounding athletics is worst crisis to have ever hit the sport

French police have announced an investigation into former IAAF president Lamine Diack

Thompson, the former Olympic decathlon champion, said the allegations struck at the very heart of the sport and likened it to both the FIFA corruption scandal and the drugs case surrounding disgraced seven-time Tour de France champion Lance Armstrong.

He told talkSPORT: 'We said when Seb Coe took over the IAAF that the first 100 days were going to define his tenure.

'If these latest developments are true then I don't think much worse could happen to the the sport than for the former president Lamine Diack to have colluded with the Russian federation over doping tests. This is a 10 or 11 on the Lance Armstrong scale. It's the worst thing.

'This is much worse than what Sepp Blatter has (allegedly) been doing at FIFA.

'When somebody is in charge of the sport and is protecting and profiteering from cheating then I don't think you can go lower. He (Diack) has undermined the very premise that sport is built on.

'All those people who have lost medals and funding and pure enjoyment, and all those spectators who have been fooled, it has been such a dereliction of duty.'

Meanwhile, five Russian athletes have been banned for drugs offences ahead of the publication on Monday of a major investigation by the World Anti-Doping Agency into doping in the country.

A statement on the Russian federation's website said three athletes had been banned on the basis on information received from the Russian anti-doping agency RUSADA and the other two disqualified on the basis of the documents received from the IAAF.

Diack is pictured with his successor as IAAF president, Lord Sebastian Coe (left), in Berlin in 2009

Hammer thrower Mariya Bespalova, pictured at the 2012 Olympics, is one of five Russians to be banned

The athletes include marathon runner Maria Konovalova, who finished second at the Chicago Marathon in 2010 and third in 2013, banned for two years for irregularities in her biological passport, and Olympic hammer thrower Maria Bespalova, banned for four years after testing positive for a steroid.

The runners Vlas Bredikhin and Yaroslav Kholopov were both banned for four years and race walker Yevgeny Nushtayev received a six-month ban, the federation said.

The IAAF scandal erupted on Wednesday when prosecutors from the Parquet National Financier (PNF) - the office that handles financial prosecutions in France - confirmed that Diack is being investigated.

Diack and his adviser Habib Cisse have been formally interviewed, sources with knowledge of the investigation have confirmed. The IAAF's anti-doping director Gabriel Dolle has been taken into custody.

Prosecutors said the investigations included a probe into allegations that Diack was paid more than one million euros to cover up positive drugs tests.

It is understood IAAF president Lord Coe, who took over from Diack in August, was at the offices at the time and volunteered to speak to the investigators.

The scandal first broke in late 2014 when German broadcaster ARD alleged a number of positive tests involving Russian athletes were covered up by IAAF officials.