Fields Medal stolen from Kurdish mathematician in Brazil

A winner of the Fields Medal, often called the "Nobel Prize of mathematics," had his prize stolen shortly after receiving it during a ceremony in Rio de Janeiro on Wednesday.

Caucher Birkar, a Kurdish refugee from Iran teaching at Cambridge University, put the gold medal, worth around $4,000, in a briefcase and soon afterward realised that it had been stolen, according to event organisers.

Security officials at the Riocentro venue, Riocentro, found the empty briefcase in a nearby pavilion. Police reviewed security tapes and identified two potential suspects.

"The International Congress of Mathematicians is profoundly sorry about the disappearance of the briefcase belonging to mathematician Caucher Birkar, which contained his Fields Medal from the ceremony this morning," organisers said in a note.

Organisers said they were co-operating with authorities to retrieve the prize.

It was the first time that the awards event, held every four years, was hosted in the southern hemisphere. 

Birkar was one of four mathematicians who was awarded this year's Fields Medal.

Given every four years, the prize goes to mathematicians under 40 and the winners were announced during the International Congress of Mathematicians being held in Rio de Janeiro.

The International Mathematical Union, which gives the award to between two and four people every four years, described the medal as made of 14 karat gold and measuring 6.35 centimetres in diameter.