William Barton, 57, from Shotton, was tucking into a packet of chilled ham he bought from Asda in Queensferry when he discovered what he desctribed as a "metal staple" lurking between slices.

There were also several metal shards spread throughout the packet, he said.

He said: "I wasn't wearing my glasses at the time and I had already eaten the first two slices when I noticed the metal.

"I must have eaten some of the shards without realising it.

"I was quite worried for four or five days afterwards, because you don't know what the health effects could be."

Mr Barton, a Shotton town councillor, added: "I always do my weekly shop in Asda and this is the first problem I've had there.

"They gave me a refund, but I've been in touch with them three times now and I just want an explanation of what happened.

"I don't want any compensation or anything like that. I just want to make sure it doesn't happen again."

Asda bosses have been left baffled by the bizarre discovery.

A company spokesman said: "We take complaints of this nature very seriously indeed, as soon as Mr Barton brought the ham back to store, we started to investigate.

"Our suppliers have confirmed that throughout the process from farm to store, our ham goes through several metal detectors, so we are scratching our heads on how this could have happened.

"We sell thousands of packets of our ham every week, and this is the only incident of its kind we have received.

"It goes with saying we are very sorry indeed."