A former Army official cleared of murdering his best friend in Sussex was today giving evidence to the Bloody Sunday inquiry.

Colin Wallace, who also worked for a West Sussex council, was based at Army headquarters in Northern Ireland when 13 civil rights marchers were shot dead by paratroopers in Londonderry in 1972.

He is the last key witness to give evidence at the inquiry headed by Lord Savile before it switches to London next week.

Ulster-born ex-soldier Mr Wallace was sacked as a Ministry of Defence information officer in 1975.

He claimed he was fired for threatening to expose a homosexual ring at the Kincora boys' home in east Belfast.

He also said he was targeted because he protested about a dirty tricks campaign against senior politicians.

In 1990 government ministers admitted records had been uncovered in the MoD which substantiated the allegations.

The Kincora affair was exposed in an Irish newspaper in 1980 and three men were convicted of sexual abuse.

Within months Mr Wallace, then press officer for Arun District Council, was charged with the murder of best friend Jonathan Lewis.

Brighton antiques dealer Mr Lewis was found floating in the River Arun at Arundel.

Mr Wallace had been having an affair with Mr Lewis's wife, Jane, but denied having anything to do with the death.

The case was labelled the It's A Knockout killing as one of Mr Wallace's duties was helping the BBC film the show.

The prosecution alleged Mr Wallace attacked Mr Lewis and left him unconscious in the boot of an It's A Knockout car before dumping him in the river.

Mr Wallace was found guilty of manslaughter in 1981 and jailed for ten years.

He served six years before the Court of Appeal overturned his manslaughter conviction in 1996.