The influential US gun lobby the National Rifle Association (NRA) has elected a former aide to President Ronald Reagan as its new president.

Oliver North, a retired US Marine Colonel, played a major role in the so-called Iran-Contra scandal.

During the 1980s he created a network which secretly sold weapons to Iran and diverted the proceeds to fund armed Nicaraguan anti-communist groups.

He later became a conservative radio host and was a Fox News contributor.

Mr North announced he was retiring from Fox News in an NRA statement announcing his new role.

The Iran-Contra scandal was arguably the major controversy of the Reagan presidency, as the US Congress had forbidden sending military aid to rebels in Nicaragua.

In 1989, Mr North was convicted of three charges of unlawfully diverting US government funds.

His convictions were quashed on appeal in 1990 as it was found that witnesses may have been influenced by previous congressional testimony.

Wayne LaPierre, the NRA's chief executive, described Mr North as "a legendary warrior for American freedom".

In a statement, Mr LaPierre said the conservative commentator was "a gifted communicator and skilled leader. In these times, I can think of no one better suited to serve as our president."

The NRA has campaigned heavily against all forms of gun control, arguing that more guns make the country safer.

On Saturday, US President Donald Trump spoke at the organisation's conference in Dallas, Texas, where he said American gun rights were "under siege".

A shooting in February at a high school in Parkland, Florida, has revived the debate about the right to bear arms with the NRA in particular facing a backlash.

Students have held demonstrations across the US to protest gun violence and have called for tighter gun control measures.