Police defend Gerry Adams arrest

Northern Ireland's police chief has defended the decision to arrest Sinn Fein leader Gerry Adams over a 1972 IRA killing, saying the evidence warranted his interrogation even though no charges have been filed.

In his first public comments since Adams' arrest and five days of police detention, Chief Constable Matt Baggott said Adams' Irish nationalist party was wrong to say that Adams was singled out for political reasons.

Sinn Fein accused what it called a "dark side" of Protestant hardliners within the force of conspiring to demonise Adams.

Baggott, an Englishman who has led the force since 2009, said on Tuesday that a judge who saw the evidence midway through Adams' interrogation believed extended questioning of the 65-year-old party leader was merited.

Adams was questioned for four days over the abduction and murder of mother-of-10 Jean McConville before being released on Sunday.