Panorama: BBC team threatened following Boxing and the Mob programme

Champion boxer Tyson Fury did not respond to Panorama's questions about his links to a suspected crime boss

A BBC Panorama team has been threatened following a programme about a suspected crime boss's influence in world boxing.

Northern Ireland police have warned of an unspecified threat from unnamed criminal elements.

The programme investigated the role played by Daniel Kinahan, named in the Irish courts as the head of one of Europe's most prominent drug cartels.

It led to calls for tighter regulation but some in boxing defend his involvement.

• The story of the suspected gangster at the heart of boxing

• 'Organised crime boss' still working in boxing

Jo Carr, the BBC's head of current affairs, said: "The BBC places the utmost priority on the safety of our teams, whose journalism plays a vital role in a free society. It is despicable and intolerable if thugs think they can muzzle a free press through intimidation.

"We will continue to throw light into even the murkiest of corners."

The courts in Ireland have accepted that an organised crime group linked to Mr Kinahan is involved in drug trafficking and execution-style murders.

The group is also suspected of involvement in a feud with a rival Dublin gang that has resulted in 18 people being murdered.

Mr Kinahan's lawyer told the programme he has no criminal record or convictions and the allegations about him being a crime boss are false and have no evidential basis.

The lawyer said: "In so far as our client's record in boxing is concerned, he is proud of his record in boxing to date."

Daniel Kinahan's involvement in world boxing was investigated by BBC Panorama

Mr Kinahan's involvement in boxing caused an outcry last summer when world heavyweight champion Tyson Fury publicly thanked him for setting up a much anticipated title fight with fellow British champion Anthony Joshua.

The criticism died down after it was announced that Mr Kinahan would no longer negotiate Mr Fury's fights and he was stepping away from boxing.

But Panorama's Boxing and the Mob programme discovered the suspected crime boss was still advising top fighters in world boxing.

Mr Fury did not respond to questions about whether Mr Kinahan was still acting as his personal adviser.

• Boxing and the Mob - a Panorama investigation - is available to view on BBC iPlayer