The recent conviction of an arms broker from Yorkshire has raised serious concerns about the murky world of the international weapons trade. Gary Hyde was sentenced to seven years imprisonment for one of the largest illegal arms deals ever uncovered: 80,000 guns and 32 million rounds of ammunition shipped from China to Nigeria - enough to equip a small army. But no-one knows where they ended up. Britain has strict regulations governing the sale and export of firearms, so how did he manage it? Where have the guns gone?

File on 4 investigates the British arms dealers brokering weapons for some of the world's most dangerous regimes. Some have done work for the Ministry of Defence. One was even a firearms advisor to the Home Office. Allan Urry asks what this means for the UK's licensing and arms export regimes, claimed to be among the best in the world.

Producer: Gail Champion.