A UVF bomb at a reservoir in Killkeel Co Down in 1969 was financed by the late DUP leader Ian Paisley, a retired British army commander has claimed.
David Hancock, a former British army company commander, was stationed close to Silent Valley when the bomb - that cut off part of the water supply to Belfast - exploded in 1969.
Speaking to BBC Spotlight for a special series on the Troubles, he said an RUC inspector based at Killkeel showed him evidence that the bomb was financed by the former firebrand preacher turned Stormont first minister.
Speaking to Q Radio today, North Antrim MP Ian Paisley rejected the suggestion that his father was involved:
At first it was thought the bomb was the work of the IRA and was used as leverage to push the then Northern Ireland prime minister Terence O'Neill from office.
Mr O'Neill had planned to give concessions to the growing nationalist minority in order to try and stabilise the state.
However, Ian Paisley and his hardline loyalist followers deemed the Unionist prime minister "a Lundy" and wanted him removed from the post.
Archive government documents uncovered by the BBC team, referred to in the first of a seven part series of documentaries, The Troubles - A Secret History, also show how the government of the time viewed Paisley's followers and the UVF as "one in same".
Read More: BBC documentary lays bare brutal political and military history of the Troubles
Mr Paisley - who ended up leading a power-sharing executive at Stormont with Sinn Féin's Martin McGuinness as his deputy - always denied any links to the UVF.
The documentary also contains previously unseen footage of a young Martin McGuinness carrying weapons and standing beside a car as a huge bomb was loaded into the back.
The bomb was driven into Derry city centre and exploded causing damage to property. Footage filmed by an American documentary crew was obtained by the BBC NI team and features in the first part of the documentary series to be aired next Tuesday on BBC 1.
