A man whom police describe as potentially dangerous to women and children was a former Sinn Féin election candidate in the North and an ex-IRA prisoner.

The PSNI has launched a massive search operation after Martin Forbes (51) from Strabane in Co Tyrone went missing.

Forbes, who also goes by the name of Drew, has breach­ed a court order which requires him to inform police of any change of address.

Police say he could be anywhere in Ireland or Britain and he could pose a risk to women and children.

Forbes has served a lengthy prison sentence for the Provisional IRA and was on the "blanket protest" in Long Kesh.

After he was released from jail, he became active in Sinn Féin and stood for the party in Strabane in the 1989 local government elections.

He failed to get elected but remained active and prominent in the party for years afterwards, according to local republicans.

When contacted by the Sunday Tribune, a Sinn Féin spokesman said: "Drew Forbes left Sinn Féin in the early 1990s. We are aware a serious allegation has been made against him of the sexual abuse of a child and the matter is being dealt with by the courts.

"This is not an historic case. It relates to allegations of abuse in the here and now. There has never been an allegation made that Mr Forbes was involved in any abuse during his time within the party.

"If such an allegation had been made he would have been subjected to party disciplinary procedures and the appropriate statutory authorities notified."

The spokes­man urged anyone with information to contact the PSNI or gardaí.

Forbes was last seen in Belfast three weeks ago. Strabane Ulster Unionist councillor James Emery said: "The local community are very worried that this man has gone missing. People hope the police find him soon."

DUP councillor Allan Bresland, said: "It is very, very worrying that a boy like that has gone on the run, especially if he poses a risk to women and children."

While Forbes hasn't been convicted of any sexual offence, a police spokeswoman said he was a "potentially dangerous person". Sinn Féin has been mired in sexual abuse scandals in recent months.

Gerry Adams' brother Liam, a suspected paedophile, is wanted by the PSNI over claims he repeatedly raped his daughter, Aine Tyrell, from the age of four. She has criticised the Sinn Féin president's handling of the case.

Gerry Adams said he believed his niece when she made the allegations in 1987. However, Liam Adams went onto become a prominent figure in Sinn Féin. As chairman of the Louth comhairle ceantair in 1996, he was the party's most senior official in the county.

He canvassed with Gerry Adams in the 1997 Dáil elections and went on to hold positions, including treasurer of a cumann, in West Belfast despite previous claims from his brother that he had long been expelled from Sinn Féin.