Suspected victims of modern slavery in the UK have been further traumatised by long delays in the Home Office ruling on their status, despite the government saying decisions should be made as soon as possible after people have been referred into its rescue mechanism for a 45-day recovery period.

The Guardian learned last month of six west African men who were rescued from British trawlers in 2017 and referred to the Home Office’s national referral mechanism (NRM) as suspected victims of trafficking for labour exploitation. Six months into this year they were still waiting for the Home Office’s visa and immigration department to process their cases. A few days after the Guardian began making inquiries about the delay, the Home Office granted them all leave to remain.

The period of limbo created great anxiety. While they waited they were dispersed and, it’s understood, living in emergency housing provided through the government’s subcontractor for support to victims, the Salvation Army. Suspected victims in the mechanism are given minimal benefits for living costs, in most cases £65 a week, reduced in some cases to £37.75 if they also make an asylum claim.

The uncertainty victims face is highly damaging, according to Kate Roberts, head of the Human Trafficking Foundation. “The NRM is meant to make things different for those who have been controlled by their traffickers, to re-empower them,” she said. “Instead they are shoved into another system where they still have no control over their lives.”

Some of the men were brought into the UK for trawler owners by agents using small regional airports with transit visas and letters claiming they were in transit out of the UK to international waters. It has been claimed that Border Force staff made calls to the alleged traffickers to collect men from the airport, thinking they were being helpful. The men then ended up on fishing vessels working what they said were extreme hours with almost no rest for days on end. They reported being required by owners to live on the boats for several months. They cannot be identified for legal reasons.

Quick Guide Modern slavery Show What is modern slavery? About 150 years after most countries banned slavery – Brazil was the last to abolish its participation in the transatlantic slave trade, in 1888 – millions of men, women and children are still enslaved. Contemporary slavery takes many forms, from women forced into prostitution, to child slavery in agriculture supply chains or whole families working for nothing to pay off generational debts. Slavery thrives on every continent and in almost every country. Forced labour, people trafficking, debt bondage and child marriage are all forms of modern-day slavery that affect the world's most vulnerable people.

How many people are enslaved across the world? The UN's International Labour Organisation (ILO) estimates that about 21 million people are in forced labour at any point in time. The ILO says this estimate includes trafficking and other forms of modern slavery. They calculate that 90% of the 21 million are exploited by individuals or companies, while 10% are forced to work by the state, rebel military groups, or in prisons under conditions that violate ILO standards. Sexual exploitation accounts for 22% of slaves. Where does slavery exist? Slavery exists in one form or another in every country. Asia accounts for more than half of the ILO's 21 million estimate. In terms of percentage of population, central and south-east Europe has the highest prevalence of forced labour, followed by Africa, the Middle East, Asia Pacific, Latin America and the Caribbean.

Who is profiting? In 2005, the ILO estimated that illegal profits from forced labour amounted to more than $44bn. The UN's global initiative to fight trafficking says people trafficking is the third-largest global criminal industry (pdf) behind drugs and arms trafficking. The ILO estimates that people in forced labour lose at least $21bn each year in unpaid wages and recruitment fees. Slavery also exists within global supply chains, generating huge profits for those who control this industry in free labour.

The Guardian first exposed this route into modern slavery in the fishing sector in Ireland in an investigation in 2015, prompting the Irish government to set up an emergency taskforce and introduce a new permit scheme. The route is still functioning. Earlier this year west African men who were brought into Belfast airport and driven across the border on to Irish vessels in the Republic were given positive decisions on their status as suspected victims of trafficking by the authorities within weeks of rescue.

Home Office delays are common in the UK, however, despite tackling modern slavery being one of Theresa May’s flagship programmes both as home secretary and as prime minister.

A report by the National Audit Office, published last December, was highly critical of the time it was taking to process suspected victims.

A Home Office spokeswoman said that since last year it would have doubled the number of officers deciding on referrals to cope with the rise in numbers of suspected victims being reported. “Modern slavery is a barbaric crime that destroys the lives of its victims, which is why we introduced the world-leading Modern Slavery Act in 2015 and have put in place the modern slavery strategy,” she said.

A package of reforms to the national referral mechanism already announced would improve support to more victims and streamline decisions, with an independent panel for an extra layer of scrutiny, she added.

Case study

Solomon was rescued from a UK fishing trawler by the British authorities last year and was immediately referred into the government’s mechanism for supporting suspected victims of slavery. An agent in west Africa had arranged the job for him and organised bringing him into the UK via a small regional airport on a transit visa for the trawler owner. He was forced to live on the vessel and said he worked 18 hours in every 24 for months without any rest days. His contract was for £800 a month paid in west Africa, with a £50 allowance each month on the boat, so he was paid a fraction of what would be the legal national minimum wage.

He spent more than six months waiting for a final decision on his status from the Home Office. The trauma of the original experience and the anxiety caused by his state of limbo area were clearly visible when he talked to the Guardian last month.

“I don’t want to remember,” he said. “It pains me a lot. We worked nonstop, all the time, no sleep, picking stones out of the conveyor belts of fish. On the fishing trips, sometimes seven days, sometimes 10 days, we only had plain pasta for days – there wasn’t enough food or water, no fruit or vegetable. I had no day of rest and I couldn’t call my family.

“The contract says you will stay on board for 12 months, plus or minus three months, and the skipper can keep your salary for two months so he can send you home if he likes. The slave trade passed a long time ago. But every day they would curse you and say: ‘You are a black slave, work!’ Things like that. It made me very angry. I was trapped – I had borrowed money to come.”

Solomon has been supported within the national referral mechanism but the uncertainty and the money difficulties his family are experiencing have taken a toll on his mental health. He has sometimes felt unable to leave his room in the safe house for up to three days at a time.

I|t’s understood he was finally granted leave to remain a few days ago, after the Guardian began asking the Home Office questions about delays in processing the cases of suspected victims of modern slavery.

His name has been changed to protect his identity.