Corrupt recruiters have demanded up to $7,500 from seafarers for the right to work at sea, a new survey has found.

The study is the latest to suggest that seafarers being forced to pay for jobs is a widespread practice within the maritime business.

More than one in five seafarers who responded to the survey said they had been asked to pay fees ranging from $50 to $7,500 with an average of $1,872.

Recruiters have also confiscated documents until they have received payment from the seafarer or from the shipping company that eventually hires them, according to the study.

“We have identified some cases (around 10%) where seafarers are still in debt because of these payments,” said researchers.

The request for money came mainly from the crewing agent appointed by the shipping company. Most cases were reported in the last three years, suggesting that it remained a live issue.

The issue appeared to be most common in India, where 35% of those who responded said they had been asked to pay recruitment or placement fees rose, according to the study of more than 200 seafarers by researchers from Liverpool John Moores University and maritime welfare charity The Mission to Seafarers.

The survey backs the findings of larger studies that have also found that the practice was widespread but few seafarers report the approaches because they do not know how to.

A survey of close to 5,000 seafarers published earlier this year by the Institute for Human Rights and Business (IHRB) and the Sustainable Shipping Initiative found the illegal practice of charging seafarers recruitment fees was widespread but mostly unreported.

The Maritime Labour Convention, known as the seafarers’ bill of rights and adopted by the UN in 2006, bans the practice of charging seafarers for jobs. The banned payments include for covering the costs of visas and medical checks.

Ben Bailey, of The Mission to Seafarers, said: “This report confirms what seafarers have told us informally when it comes to the scourge of illegal fees and charges that so many of them are being coerced into paying in return for employment.

“If shipping wants to be able to attract and retain the talented seafarers that it relies upon, it will require meaningful action from national and international regulators, shipping companies, and the recruitment sector to drive out this practice.”