The government has requested the extradition of a Briton held in Pakistan, in connection with a murder committed in 2002.
Rashid Rauf was arrested in Pakistan earlier this month over an alleged plot to blow up US-bound aircraft, Pakistan's Foreign Ministry said.
The Home Office confirmed the UK had made a request for his extradition, but it was over the unrelated murder.
Scotland Yard declined to discuss which murder case the request related to.
A Home Office spokesman said on Monday: "The UK has submitted an extradition request to the Pakistan authorities in respect of a murder committed in April 2002."
Mr Rauf, who has been held in the country since 9 August, has previously been described by Pakistan's government as a "key person" in the "suspected conspiracy".
Tasnim Aslam, a spokeswoman for Pakistan's foreign ministry, told a news conference the British government "had sought his extradition and the matter was under consideration".
Pakistan has no extradition treaty with the UK, but on Sunday the country's Interior Minister Aftab Khan Sherpao said it would consider deporting Mr Rauf to London if any such request was made.