Bicester mayor John Cozens has faced many challenges during his year in office.

But he has just discovered another occupational hazard - losing the centrepiece of his mayoral chain.

Now Mr Cozens is appealing for the public's help in finding the missing £5,000 medallion.

The 73-year-old from St Anthony's Walk, Bicester, thinks the gold centrepiece fell off his chain on the way to a charity dinner at Oxford Town Hall on Saturday.

He said: "I had it on when I left the house in Bicester.

"My daughter drove me to Oxford. She parked opposite the Town Hall and we got out quickly because there was a taxi behind us hooting its horn.

"We had to walk a few yards up, cross the road and go into the Town Hall. And when I took my coat off I thought Oh my God - it is missing'. My heart went in my mouth."

Mr Cozens and his wife Beryl retraced their steps along St Aldates, but could not find the missing medallion. He said: "I checked everywhere. My wife did not sleep that night at all. I have checked the house and my daughter's car."

Mr Cozens, who has been a town councillor for nearly five years, said he did not usually put his chain on until he arrived at an event because it was heavy and made it awkward to drive.

But the Tory councillor said he was in a rush after watching the Six Nations rugby and, because he was not driving, wore it on the 30-minute journey to Oxford.

He added: "The original chain is away being repaired and we had a makeshift chain where the clasp is not very good.

"It had fallen off in the morning while I was visiting St David's Barracks, but I noticed straight away and put it back on.

"It is the pride of the town. It has got sentimental value.

"I should imagine it had come loose and dropped as I got out of the car. I think someone has picked it up, thought it looked nice, and put it in their pocket. Hopefully they will hand it in or get in touch with us. There will definitely be a reward."

Bicester Town Council leader Debbie Pickford said the medallion was about the size of the palm of her hand and had a lattice design around the edge.

It is also engraved with the words 'Bicester Town Council'.

It was donated to the town about 45 years ago by a resident who had won the football pools.

She said: "I think everybody would breathe a great sigh of relief if somebody handed it in."

Anyone with information can call the council on 01869 252915 or the police on 08458 505505.