Colin Howell, the convicted double killer, is to be questioned about a new allegation of serious sexual assault.
The former dentist, 58, will be brought from jail today for interview, informed sources disclosed. The allegation relates to a historical incident, according to one of those familiar with the case. Howell is serving a minimum of 21 years for the murders of his wife, Lesley, and a police officer, the husband of his former lover Hazel Stewart.
The bodies of Lesley, 31, and Constable Trevor Buchanan, 32, were found in a fume-filled garage in Castlerock, Co Derry, in 1991. Police believed they had died in a suicide pact after discovering their partners were having an affair. Nearly two decades passed before Howell confessed to both killings.
He pleaded guilty to the murders in 2010, implicated Stewart in the plot and went on to give evidence against her at her trial. In March 2011 Stewart was unanimously convicted of both murders and ordered to serve at least 18 years. Since then the former Sunday school teacher has failed in a series of attempts to have the verdicts overturned.
Howell is also serving five and a half years in Maghaberry Prison near Lisburn for sexually assaulting five women at his dental surgery in Ballymoney, Co Antrim, between 1998 and 2008. He is expected to be questioned at a Belfast police station over the latest allegation.