A 71-year-old man has been arrested in Pakistan in connection with the murder of Pc Sharon Beshenivsky, who was shot while on duty in 2005.
West Yorkshire Police said Piran Ditta Khan was held on Tuesday following an operation involving the National Crime Agency and local partners.
Khan appeared in an Islamabad court on Wednesday, where his extradition was discussed. He was remanded in custody to next appear at court on January 29.
Pc Beshenivsky was shot while responding to a robbery at Universal Travel in Morley Street, Bradford, on November 18 2005.
Detective Superintendent Mark Swift said: "I would like to thank the National Crime Agency officers in Pakistan and partners who have made this arrest possible.
"This is a major development in this long-running investigation and their assistance in this matter cannot be understated.
"We are continuing to liaise with partners in Pakistan to process Khan's extradition with the intention of returning him to the UK to face court proceedings."
Pc Beshenivsky was a 38-year-old married mother of three with two stepchildren, and was a probationer with only nine months' service when she was killed.
Her colleague, Pc Teresa Millburn, was also shot but survived to later give evidence at the trial of members of the armed gang who were charged with being involved in the murder.
Six men were later jailed at Newcastle Crown Court, but Khan, a former bouncer who was suspected of being the gang organiser, had fled abroad.
In 2016, West Yorkshire Police issued a fresh appeal for find him as he remained at large despite a £20,000 reward for information leading to his arrest.
