Serial child killer Robert Black, who murdered Ballinderry girl Jennifer Cardy, tried to hunt down the identical twin sister of one of his alleged victims in Co Donegal, a retired detective has claimed.
Chris Clark, who is investigating cold case murders by Black, claims to have found evidence that the killer went to Ireland in 1978 in search of the twin sister of seven-year-old Mary Boyle from Cashelard, near Ballyshannon in Co Donegal.
Mary is believed to have been murdered by Black in March 1977, but her body has never been found.
Black is serving life sentences for the murders of four girls, including nine-year-old Jennifer in 1981.
Mr Clark (68), a former police intelligence with Norfolk Constabulary, is convinced Black was also responsible for killing Mary.
New evidence suggests Black was a regular visitor to both sides of the border in the 1970s and is recorded on police files for unlawful after-hours drinking at a pub close to where Mary was staying.
Mr Clark said: "His van was also noted parked regularly behind the Old Cope Yard at Dungloe, and one witness later recalled hearing a whimpering or crying about the time of Mary's disappearance coming from within Black's van."