Edwin Poots in appeal over 'seal killings' in NI
Environment minister Edwin Poots has appealed for information following the death of five seals in the past week.
Post mortem results are pending following the discovery of the seals in Strangford Lough.
But the Department of Environment (DoE) said it appears one was shot, one had been cut and two had "corkscrew" type injuries.
Mr Poots has urged anyone with information on the unlawful killing of seals to go to the police.
"Despite warnings from the Northern Ireland Environment Agency in the media, there are still people who have no qualms about carrying out this inhumane practice," he said.
"I would urge anyone who has information on who is behind it to come forward to the PSNI or to us."
The NIEA last month appealed for information following an "unusually high number of unnatural seal deaths reported along the County Down coast".
The DoE said the police, NIEA and other organisations were liaising in an attempt to stop the killings but were "no nearer to identifying the perpetrators of many seal deaths".
It said some deaths, particularly those with 'corkscrew' cuts, may have resulted from interaction with the 'shrouded' propellers on a small number of vessels.
Mr Poots added: "Now, in the light of the latest deaths, it is even more important that we find out who is behind this and put a stop to it.
"Anyone convicted of deliberately or knowingly killing or injuring seals is likely to face a substantial fine."
Declan Looney of the NIEA, said the agency was liaising with the police and other relevant organisations "in an effort to stop these killings" and there was "a growing sense of frustration that this is still happening".
Police Service of Northern Ireland Wildlife Liaison Officer Emma Meredith said the latest discoveries appeared "to confirm a very worrying trend".
"Seals are protected under law and killing them constitutes a serious offence," she said.
"The PSNI will vigorously investigate any reported instances and will not hesitate in reporting those involved to the Public Prosecution Service."