A Cambridge professor who won one of the most prestigious prizes in mathematics, the Fields Medal, has had his award stolen in Brazil.

Professor Caucher Birkar, a Kurd, came to the UK as a refugee from Iran.

He was one of four people honoured for their contributions to mathematics and had said that he "couldn't imagine that this would come true".

But just minutes later, he discovered that the 14-carat gold medal had gone missing.

According to Brazil's TV Globo, he left it along with his wallet and phone in a briefcase on a table at the convention centre where the event was taking place.

He alerted security staff when he noticed the case was missing and they later found the case, but both his medal and his wallet were no longer there.

Who is Professor Birkar?
Caucher Birkar was born on a farm in Kurdistan Province, near the Iran-Iraq border, and was raised during the eight-year war between the two neighbouring countries that broke out in 1980.

He told Quanta magazine that while he was growing up, his maths club in Tehran had pictures of Fields Medal winners lining the walls.

"I looked at them and said to myself, 'will I ever meet one of these people?' At that time in Iran, I couldn't even know that I'd be able to go to the West," he said.

While studying for his undergraduate degree at the University of Tehran, he travelled to the UK and sought political asylum there.

He established a reputation within academia with his work on birational geometry and has previously won the prestigious Leverhulme Prize.

The Fields Medals are awarded every four years to the most promising mathematicians under the age of 40.

Each winner receives a C$15,000 ($11,500; £8,800) cash prize.