LONDON (AFP) - The family of a British hostage believed to have been killed by his Nigerian captors said on Monday that he had been "deprived of meeting his first grandchild."

Foreign Secretary William Hague said on Sunday that Brendan Vaughan, 55, from Leeds in northern England, was "likely to have been killed" along with six other foreigners.

In a statement issued by the Foreign Office, Vaughan's family described the construction worker as "a lovable rogue" who "lived his life to the full and on his own terms.

"He has been deprived of meeting his first grandchild, a baby girl to be born in May," they said.

"Brendan may be gone but will be never forgotten." Nigerian Islamist group Ansaru on Saturday claimed to have killed the foreign hostages abducted from a construction site last month in the country's restive north.

A video posted online claims to show the bodies of some of the hostages.

The grainy and silent video posted on YouTube appears to show at least four victims. The images match screen shots released at the weekend along with the claim that the hostages had been executed after their abduction last month.