© MI5 headquarters in central London.
Britain's MI5 security service deliberately covered up the sexual abuse of vulnerable boys in a notorious children's care home in Belfast, Northern Ireland, an ex-Army Intelligence officer claimed on Tuesday.

Brian Gemmell, a former captain in Britain's Intelligence Corps, said security service chiefs at MI5 ordered him to"stop digging" when he reported suspicions of a pedophile ring at the Kincora care home for boys in Belfast, Northern Ireland.

Gemmell made the disclosure during a meeting with child abuse victim Richard Kerr in an exclusive Channel 4 News interview. Kerr was sent to the Belfast care home in the mid-1970s at age 15.

Kerr said he and two other boys were abused in Kincora in the mid-1970s, trafficked to London in 1977 and subsequently molested by a number of "very powerful" members of a Westminster pedophile ring.

He claims he was sexually abused by British politicians and senior establishment figures at a luxury Dolphin Square apartment in Westminster, and also at Elm Guest House in west London. Both locations are being investigated by Scotland Yard, following allegations that a Conservative MP murdered a young boy.

Campaigners battling for justice for victims of child abuse argue that Kerr's account provides evidence of a concrete link between powerful pedophile rings that operated in Belfast in London during the 1970s.

'I'm sorry'

MI5 has long been the subject of allegations it concealed child abuse to enable the gathering of intelligence on Loyalist MPs during the troubles in Northern Ireland. But it has also come under fire for suppressing evidence of child sex abuse in a bid to protect powerful establishment figures responsible for these crimes.

Gemmell, who was a military intelligence officer in Belfast during the 1970s, submitted a report examining claims of child abuse at Kincora to a senior MI5 officer in 1975. Much to his surprise, however, he was instructed to abandon the investigation.

Speaking on Channel 4 News, Gemmell apologized directly to Kerr.

"That's the thing that hits me - that if I really pushed the thing through, you could have been rescued. I'm sorry," he said.

Gemmell said Kerr's perspective provides evidence of a link between the historic pedophile rings that operated in Belfast and London.

"I think Richard's transporting over to the United Kingdom mainland to be abused, rather than just being abused in Northern Ireland, speaks volumes. It ties the two together," he said.

MI5 has previously been accused of covering up allegations of child abuse against Liberal MP Cyril Smith after they surfaced in the 1960s, the 1970s and the 1980s. The MP died in 2010.

Revelations stemming from Kerr's account of the abuse will likely add weight to calls for allegations regarding Kincora to be included in the scope of Britain's judge-led abuse inquiry.

The inquiry is set to examine whether state and public bodies such as governments, the Church, charities and the BBC failed in their duty to protect children. It was sparked by allegations a powerful pedophile ring operated in Westminster during the 1980s.

The investigative probe, spearheaded by New Zealand High Court judge Justice Lowell Goddard, will likely have access to historic MI5 files.

Grave allegations

Last month, grave allegations that Scotland Yard had suppressed evidence, hindered police investigations and covered up child sex offences in the 1970s to protect the identity of MPs and Metropolitan Police officers were brought to the attention of Britain's Independent Police Complaints Commission (IPCC).

Home Secretary Theresa May said at the time that historic child sex abuse was "woven, covertly, into the fabric" of British society.

In late March, allegations of satanic worship and child abuse involving the late Tory MP Enoch Powell were also handed to staff investigating the historic pedophile sex ring alleged to have operated in Westminster.

Powell, who died in 1998, was one of a series of high-profile figures named in a Church of England (CofE) review into historic sex abuse, which was given to Scotland Yard by the Bishop of Durham, Paul Butler.

The claims are reported to involve the abuse of children, as well as satanic rituals.

In February, lawyers representing victims of abuse at Kincora told the High Court in Belfast that MI5 had knowledge of historic child abuse at the home but had turned a blind eye to it to protect those who were responsible.

The children's care home was managed by William McGrath, who headed an extreme loyalist Protestant organization known as Tara. He was also allegedly an MI5 informant.

McGrath and two of his staff were sentenced in 1981 for sexually abusing young boys in their care.