A British nuclear expert who plunged to his death a day before talks with Iran began may have been murdered.

The United Nations official, named only as Timothy H by police, plunged 37m (120ft) to his death from the 17th floor of the UN's building in Vienna on Tuesday.

'Whenever there is a case where others may have been involved we will investigate all the possible scenarios. Murder is one possibility. Also suicide,' said a police spokesman.

Detectives are believed to have found no suicide note. The 47-year-old was a member of the Comprehensive Nuclear Test Ban Treaty Organisation and joined the UN's talks with Iran over its nuclear programme.

Four months ago another UN worker, believed to be British, fell from the same building.