The 12-year-old was killed by Ian Brady and Myra Hindley more than 40 years ago.

He is one of five children known to have been killed by them in and around Manchester in the early 1960s.

Greater Manchester Police (GMP) confirmed they have been searching Saddleworth Moor, to the north-east of Manchester.

But they refused to confirm reports that a US spy satellite or specialist army teams from Northern Ireland were used in the search.

Chief Superintendent Steve Heywood, head of GMP's Serious Crime Division said: "We can confirm that an operation has been active over the past three years with the aim of finding Keith Bennett's body.

"As part of the operation, at periodic intervals, work has been carried out on Saddleworth Moor. We have kept Keith's family updated at every stage of this operation.

"It is important for us to stress that we have not found Keith's body, and it would be wrong to raise anyone's expectations - most of all those of his family - that we know where his body is or that its discovery is imminent.

"We have always been committed to finding Keith's body and our current operation is the latest in a series carried out by Greater Manchester Police over the years to locate Keith's remains and finally lay that little boy to rest."

Hindley was jailed for life in 1966 with her lover Brady for the murders of 10-year-old Lesley Ann Downey and Edward Evans, 17. Brady was also convicted of murdering 12-year-old John Kilbride while Hindley was found to have been an accessory. In 1987 the pair confessed to killing Keith Bennett and Pauline Reade, 16.