The 25-year-old policeman died on 2 April last year when a device planted underneath his car exploded outside his Omagh home.

In a telephone bomb warning at around midnight on Sunday, a caller claimed a bomb had been left outside Councillor Harold Andrews' Rosslea home.

The following day, his son uncovered a device, which the army bomb squad later declared to be viable.

On Tuesday, a man called the UTV newsroom to claim that the device was not left as part of an attack on Cllr Andrews.

Instead, he described it as "a failed attack on the security forces" and claimed the horizontal mortar had failed to detonate after it was fired at a passing police patrol.

The caller said the device had then been placed in a safe area. He added that he belonged to the same dissident group that killed Constable Kerr.

But Cllr Andrews said the long grass in which the bomb was left was not safe.

"I would be sceptical of that claim," he told UTV, pointing to "the fact that it was planted on my property and it was nearly hidden."

Sinn Féin MLA for the area Sean Lynch has spoken out against those who left the device at the Andrews' home.

"These people have been causing disruption for a number of years. There's absolutely no support in this day and age for it," he said.

Police have called for anyone with information about the incident to come forward.