Authorities in the Philippines are seeking the extradition of a former US Marine as a suspect in the killing of Belfast man David Balmer.
The authorities say they have recovered guns used in the killing and recovered blood-splattered jeans a suspect tried to burn.
Over 20 months ago the bodies of the police officer and his girlfriend were found in a Philippines bedroom.
Mr Balmer, 54, and 26-year-old Elma de Guia were found dead on 2 September 2011 in an Angeles City home of his friend.
Timothy Kaufman, 35, was arrested last month near his grandfather's upstate New York home.
A detention hearing related to his extradition to face murder charges will be held in a federal court in Albany.
Philippine authorities are seeking his return in connection with a premeditated killing in an area known for its club scene.
Within three months of the killing, Mr Kaufman and two other men were charged with two counts of murder.
Mr Kaufman was identified by watchmen and by surveillance footage as one of three men in a vehicle that entered the residential subdivision the night of the killings.
Also charged are Joseph Tramontano, an American, and Jesus Santos Jnr, a Filipino, who police say was the driver.
Mr Santos was arrested in March. Another man is believed to be at large in Asia.
Court papers filed in Mr Kaufman's extradition case allege that after the killings, he asked his maid to burn the contents of a garbage bag that contained shoes and clothes worn by Mr Kaufman and Mr Tramontano.
In a separate incident, Mr Kaufman asked his maid: "Can you bury something for me?" and handed her two guns wrapped in a bath towel, the papers say.
The maid turned the guns over to the police, who determined they were used in the killings.
Police said the recovered jeans had tiny blood splatters.