Police have kept body parts in almost 70 cases of unexplained and suspicious deaths in Northern Ireland without informing the families of the victims.
It is understood that between 1960 and 2005, tissue samples in 67 cases across the province were retained by police.
Some of the cases involve high-profile people, UTV reported, including up to 40 IRA murder victims in north and west Belfast.
Police said that samples would have been held as part of investigations and have added that they are now visiting the families of those affected.
In a statement, the Human Tissue Authority (HTA), which ordered an audit in 2010, confirmed that it had completed a full list of all Category 3 human tissue, including significant body parts such as skulls and organs.
“The audit has enabled the PSNI to identify and consider the most appropriate way of sensitively dealing with human tissue no longer required to be held for criminal investigations,” it added.
Police have said that they deal with families on a confidential basis and that details of the samples could not be discussed.
Policing Board member Conall McDevitt has said that the revelations will have caused pain to families.
“I would expect the PSNI to acknowledge the pain they have caused to families who are now learning that tissue belonging to loved ones had been held without their knowledge,” said the MLA.
Fellow board member and DUP MLA Jonathan Craig said he could “only imagine the pain and anguish for families” and the police now needed to apologise to those involved.
“This will be essentially re-opening the deaths of their loved ones,” the DUP MLA said.
Last week, it emerged that two English police forces — Hampshire Police and City of London Police —had retained human tissue in unexplained death cases without having notified relatives.
Under the Police and Criminal Evidence Order, police can keep material taken from bodies during post-mortems and are not obligated to get consent from relatives.
A statement from the PSNI stated: “Specially trained Family Liaison Officers are now visiting those families affected to inform them and to discuss with them what their options now are.
“We know that this will be an incredibly difficult time for those families involved and we will provide all the possible support we can to them.”
The 67 tissue samples came to light during a national audit of police forces across the UK.
It is understood that some parts kept could include skulls, bones and organs, with some cases connected to crimes committed during the Troubles.
The UK-wide audit is due to be published on May 21.