Thieves have stolen 16 life-saving belts that were erected alongside riverways following the death of a young man who drowned in Strabane.
The life-saving devices were installed across the Strabane district following the inquest in April into the drowning of 21-year-old Dale Alexander.
At the inquest senior coroner John Leckey concluded that Dale, from Millhaven in Sion Mills, died from drowning in fresh water while swimming with his friend at the weir on the River Mourne on June 1, 2009.
It emerged at the inquest that life-saving safety equipment was still missing almost a year on, prompting Mr Leckey to write to Leisure Minister Nelson McCausland about the issue.
Strabane Council has since agreed to erect two new warning signs with throw lines at Mournside Walk in Sion Mills. Others were also erected at Riverside Walk, Meetinghouse Street, Strabane, the disabled angling ramp at Melvin, Strabane, and Derg Castle, Castlederg.
But since May one of the throw lines has gone missing from Sion Mills, six more from Castlederg and a further nine from the Strabane sites.
Strabane District Council's chairwoman councillor Michaela Boyle has called for local people to help monitor the life-saving equipment.
Ms Boyle said: “Everyone has a role to play in maintaining the district's lifesaving equipment. Damage or theft of the throw lines could result in the tragic loss of life.
“While there is obviously a financial cost of vandalism to be borne by the ratepayers, the serious risk is to human life caused by the deliberate damage to this equipment.
“We need public co-operation to ensure that this equipment can fulfil its purpose, if needed.”
The council has urged anyone who sees others tampering or in possession of a throw line to report immediately to the council or the PSNI.
Local people are also being asked to report any damaged or missing throw lines immediately to Strabane District Council.
The council has now forked out £800 for the replacements and has ordered a further six to have in stock for future replacements.
Life-saving devices were installed following a report from a specialist consultant on safety issues at council sites adjacent to rivers.