Families of people who disappeared on the perilous journey from Africa to Europe have said they were asked to pay hundreds of euros in exchange for information about what had happened to their loved ones.

In interviews with the Guardian, three families recounted how, as part of their searches for missing relatives that had gone on for years, they had made contact with people they believed to be connected to an NGO in southern Spain who said they were able to help them.

Each of the families said they were asked to hand over at least €200 (£170) with the promise that they would receive information about the whereabouts of their relatives. One person said he was promised photographs of his relative’s body in a police morgue. None of the families paid the funds.

Their allegations highlight the obstacles that the families of migrants often face as they attempt to trace the steps of their missing relatives, from navigating foreign bureaucracy and language barriers to the lack of centralised data or uniform process for dealing with the thousands who die each year attempting to cross into Europe.

An investigation published by the Guardian in December revealed how this legislative void had resulted in people being buried in unmarked graves across the EU at a scale unprecedented outside war.

The lack of any formal procedure, combined with the desperation of families to obtain any news of their loved ones, has created a terrain that is ripe for exploitation.

A relative of an Algerian man who went missing more than a year ago said he was asked for €250 by a man who said he would be able to enter a police morgue and take a picture of the body of his relative.

“It was really bizarre,” said the relative. “How can these men have access to the corpse when this is not the case for those who have relatives that have disappeared?”

Another person, whose family member set off from Algeria in 2020, said his family was asked to pay €200 after being told that his missing relative was in a prison in the Canary Islands in Spain. The family hired a lawyer who was unable to verify this claim. The relative said he was also told not to contact police as it could jeopardise efforts to locate missing loved ones.

For the brother of a man who left Algeria in 2021, the request for €200 allegedly came after he was told that the small boat in which his sibling had been travelling had been sent to a secret location as it was deemed to contain “dangerous contents”. The money would allow him to obtain information about the prison or detention centre where his brother was being held, he said he was told.

“The problem is that the authorities are not that helpful,” he said. It paved the way for those who had spotted an opportunity to take advantage of these families, he added. “After three years we haven’t had any news. We just want to know where he is.”

The two people accused by the families did not respond to a request from the Guardian, nor did the NGO to which they are believed to be linked. In a statement posted on social media last week, the organisation criticised what it described as a campaign of “lies and defamation”. It also denied the “falsehoods that seek to disparage our work and undermine the trust” that the families of missing migrants had put in them.

The NGO added that it was not under investigation by any authorities. “The accusations levelled against us are false,” it said.

Spanish police said last week that 14 people had been arrested amid accusations that they had sought to profit off the relatives of people who had drowned while trying to reach Spain in small boats.

The suspects faced a range of charges including fraud, falsification of public documents and disrespecting the deceased, police said.

The suspects used social media to contact families “offering them false information regarding the whereabouts of their loved ones in exchange for money”, police said in a statement. “The network had for years been profiting off the family members in Morocco and Algeria of those who had disappeared (and) died at sea while trying to reach Spanish coasts in small boats,” it added.

If the suspects heard of a shipwreck, they would again try to contact families, offering to help carry out a “false search” for the people onboard, police said. “All of this was done with the requirement of prior payment, with the justification that this was the only way to proceed in Spain for the identification and repatriation of the bodies.”

The suspects reportedly include several public employees who worked at forensic institutes in southern Spain and who allegedly allowed the bodies of migrants to be photographed. Police said the investigation had been launched after spotting several of these photos, which were allegedly later used to pressure families into signing repatriation contracts with specific funeral homes, on social media.

Two of the three people who spoke to the Guardian confirmed they had not been contacted by the police.

Organisations that work with the families of missing migrants have long called for the creation of an office that can work with such families.

“There’s a complete legal vacuum,” said Maria Ouko, a volunteer who helps families in Algeria looking for relatives. “There are no institutions that offer clear support to families looking for their missing people. So there are scams, there’s everything,” she added.