Thieves are being blamed for delays in patient operations after hundreds of replacement joints were stolen from a factory, it emerged today.

Some 876 metal joints were stolen from the Doncasters Medical Technologies factory in Sheffield.

The joints were not ready for medical use, but police said they were worth around £60,000 on the scrap metal market.

The burglary has left the company five weeks behind its production schedule, and police appealed to the thief to return the goods so that patients would not have to wait longer than necessary for their operations.

The joints, which measure around two inches in diameter and were made from expansive cobalt chrome, were packed in crates which were stolen from the factory in Parkway Close last Thursday.

A South Yorkshire police spokeswoman said today: "Hundreds of patients may face weeks of delay because of this burglary.

"Police and the manufacturers are appealing to the thief to return the joints so that people will not have to suffer pain for longer than they need to because their operations have to be postponed."

The suspect was described as a white man, aged between 20 and 30, of slim build, with receding brown hair. He was wearing dark clothing.

Police said they were also looking for a Vauxhall Vectra or Peugeot-style car believed to have been used in the burglary.