It was the summer of 2017 and Miguel Roldán took 20 days of annual leave from his job as a firefighter and headed to the Mediterranean. It wasn’t the sparkling waters or pristine beaches that lured him but the desperate faces of migrants featured in newspaper and television reports as they attempted to make the perilous crossing from Libya to Italy.

The stretch of sea between the two nations is one of the most popular routes for migrants and refugees to enter Europe, and by the time Roldán had finished his stint on board the Iuventa – the converted fishing boat being run by the German NGO Jugend Rettet – he had helped rescue 5,000 of them. Once he returned to his day job with the underwater unit of the Seville fire department, the remaining crew members went on to rescue another 14,000.

“I saw a lot of pain, suffering and death,” recalls Roldán. “It was horrific. We tried to do everything legally and came up against a lot of bureaucracy, and that actually cost a lot of migrants their lives. At times they were left to drown because we hadn’t been given permission by the Italians to rescue them.”

Despite trying to navigate Italy’s legal territory, Roldán and his six other crew members are now facing up to 20 years’ imprisonment after being accused by authorities of aiding illegal immigration and assisting human traffickers. Italian police seized the Iuventa in August 2017 using anti-mafia laws, with a judge ordering an investigation that could result in a trial later this year.

Simply returning migrants to Libya to face more suffering is not the answer. Where’s the morality in all this? Miguel Roldán

Roldán, 32, was in London last week to talk about his experience and what he claims is the criminalisation of NGOs trying to rescue migrants. He also recently addressed the European parliament and is speaking at other events across the continent. His focus was back on Italy, however, following the arrest of Carola Rackete, the captain of the rescue ship Sea-Watch 3, which was operated by the Spanish NGO Open Arms.

Rackete defied officialdom and forced her way into Lampedusa port to bring 42 migrants ashore and was placed under house arrest. She was freed by a judge last Tuesday, but still faces a possible prison sentence with Italy’s deputy prime minister, Matteo Salvini, claiming that her actions were “politically motivated”. The rightwing minister was responsible for introducing tougher legislation, criticised by the United Nations and campaigners, which has resulted in migrant rescue volunteers facing lengthy jail sentences, fines of up to £14,000 and a “closed ports” policy.

An NGO migrant rescue operation aboard the Iuventa, in the Mediterranean. Photograph: Zohra Bensemra/Reuters

Salvini faces further challenges: yesterday the Alex, another charity rescue boat carrying 41 more shipwrecked migrants, docked at Lampedusa but was prevented from disembarking, while the German charity Sea-Eye’s vessel, Alan Kurdi, arrived in the waters off the island.

Roldán said: “Saving lives should not be about politics but humanity. NGOs are rescuing migrants because governments have abandoned them. It’s not just about Italy, it’s across Europe. Saving lives is not a crime. Simply returning migrants to Libya to face more suffering is not the answer. Using military ships to keep migrants out is not the answer. Where is the morality in all this?”

Last week members of Open Arms brought one of their rescue ships to the European parliament in Strasbourg to highlight the criminalisation of NGOs rescuing migrants and met MEPs to discuss the issue.

Roldán, who also carried out rescue missions in the Aegean Sea in 2016, said he was driven to volunteer in the Mediterranean because of the injustice with which migrants are treated and a desire to save lives. He revealed that his most haunting memory was rescuing a mother who was screaming for her baby, which was on a half-sunk ship surrounded by floating bodies. When he went on board he found the baby dead and signalled this to her. He added: “The look on that mother’s face will live with me for ever. I felt so helpless.”

According to recent data from the UN Refugee Agency (UNHCR) and the International Organisation for Migration, 1,940 people have reached Italy from north Africa since the beginning of 2019 and almost 350 have died en route – putting the death rate for those crossing at more than 15%. In total, an estimated 600,000 migrants have made the crossing since 2014, with more than 14,000 reported killed or missing while making the trip.

Roldán maintains that it is the living and not the dead that keep him awake at night. He said: “The person who dies is no more; it’s the living who have to cope with all the trauma and rebuild their lives. I always wonder what happens to the people that have been rescued? They’ve gone through terrible ordeals. How do you overcome something like that?”

Roldán insists that he is not afraid to go to prison, although even “one minute” behind bars would be an injustice. He is barred from entering Italy and the Iuventa remains impounded, but he is adamant that if he is cleared he is heading straight out into the Mediterranean to do what he knows best.

“I’m a fireman, I rescue people and save lives. It’s in my blood,” he said.