An art security expert has defended his decision to use a former art criminal to help track down two stolen masterpieces.

David Duddin, 57, has served half of a nine-year prison sentence for handling a stolen Rembrandt.

I want to stress I am not solely in this for the money

David Duddin

He has been engaged by Charles Hill, security adviser to the Historic Houses Association, to find works stolen from two stately homes.

"Anybody who can, within reason and legally, help is more than welcome to try," said Mr Hill.

"It was my idea to see David Duddin - since he was in prison he could help when he came out.

"The main thing is you don't commit a crime."

The ex-prisoner has been using his former criminal contacts to make inquiries about the paintings, and has claimed that recently he came close to the art thieves.

The Marquess of Bath wants his painting back

He is also publicising a �100,000 reward for the return of each painting, put up by trustees and insurers.

Security adviser Mr Hill was recruited by Lord Bath and Lord Chomondley to find stolen paintings by Titian and Jean-Baptiste Oudry.

The Titian, Rest On The Flight To Egypt, was stolen from Lord Bath, owner of the Longleat estate in Wiltshire, in 1995.

The White Duck, painted in 1753 by Jean-Baptiste Oudry, was taken from Lord Chomondley's Houghton Hall in Norfolk in 1992.

Mr Duddin has said he believed the two pieces were still in the British Isles, although he did not know exactly where.

He said he thought the works had gone through several pairs of hands and were no longer in the possession of the original thieves.

Mr Duddin, who is being paid expenses for his efforts, added: "I want to stress I am not solely in this for the money.

"I want the paintings to go back to their rightful owners."