British Ambassador Christopher Prentice said the British government was "committed to working for the release of all those held and I appeal again to those responsible to release these men," The Times of London reported.
Computer consultant Peter Moore and four security guards, were captured at the Iraqi Finance Ministry by 40 gunmen in a mid-morning attack May 29, 2007.
Prentice also issued a broad appeal for information about the hostages.
"Here in the British Embassy in Baghdad, and in our consulates in Basra and Irbil, we wish to hear from any person who has information about these five men or anyone who may be able to bring about their safe release," he said.
The kidnapping sparked a manhunt by U.S., British and Iraqi forces, which is continuing, the British newspaper said.