McCarthy: 'Witch-hunt'

His actions have been discussed on a number of occasions at council meetings, and councillors were recently told that there were no powers to prevent his exploration of the tunnel-type system he uncovered.

In a 10-page statement, Brian McCarthy has accused various authorities who took an interest in his activities of "Siege-like attacks" on his home and of showing "total indifference and total disregard" for him, to the point where he alleges they forced him into hiding. He has also accused them of refusing his appeals to explain himself.

"We were not told or invited to participate in any way or asked to give my view at all, and we have been left not knowing what they were doing: The Roads Service sending me threatening letters warning me not to dig in the tunnels when we were breaking no laws whatsoever and then reporting to Derry City Council naming me at every meeting, knowing we had broken no laws," he said.

He continued: "We have committed no crime. We have broken no laws at any time. As for the PSNI and Fire Service being called out on Wednesday, December 16, when I was not in the building but in the library studying some of my findings, when I asked them to tell me who sent for them all they did was hand me the callout sheets.

"By law, if an investigation was going on after the first meeting, we should by law have been informed of what was going on, but we have received nothing. We are not terrorists and we are not guilty of any offence," he said.

Condemning what he called "the clandestine gathering of information by public representatives," Mr McCarthy said he was now seeking legal advice and was considering legal action for harrassment and intimidation.

Asked to respond to Mr McCarthy's claims, a spokesperson for Derry City Council said the Council was "working closely with other statutory agencies and government departments in the interests of public safety and the need to protect the fabric of the historic city within the Walls from uncontrolled and unregulated excavations".

"The city council is happy to meet with Mr. McCarthy to discuss any issues he may have. However, public safety and the protection of the city's heritage will always be the priority of the city council. Excavations for historic or archaeological purposes are the subject of regulation, albeit the city council has no direct function in that regard."