In a bizarre twist, a Westminster seat in Northern Ireland will be competed for by a man once accused of killing the father of another candidate.

Sinn Fein Assembly member Francis Molloy was once named by a Unionist member in parliament as one of those responsible for the death of  the father of agreed Unionist candidate Nigel Lutton.

Frederick Lutton, a former police reservist was gunned down in 1979. Molloy has strongly denied any involvement.

Four contenders in all are battling for Martin McGuinness' seat as MP for the Mid Ulster constituency. McGuinness is stepping down to concentrate fully on is Deputy First Minister job.

The four contenders are Sinn Fein Assembly Member Francie Molloy, independent Nigel Lutton, the Social Democratic and Labour Party's Patsy McGlone, and Eric Bullick of the cross-community Alliance Party.

According to the Irish Independent, Stormont Deputy First Minister McGuinness said he was resigning his Westminster seat, which was run in 1997, as part of his party's policy to end double-jobbing in politics.

Molloy, the principal deputy speaker at the Stormont Assembly, will attempt to retain the solid Sinn Fein seat and is defending a sizeable majority of more than 15,300.

Lutton, the so-called unionist-unity candidate, is set to be Molloy's main rival.

The by-election will take place on March 7.