A British inquest jury concluded today that police lawfully killed a man whose shooting in 2011 sparked deadly riots across the country.

Family members and supporters of Mark Duggan shouted obscenities and smashed a door after the decision was read out at the Royal Courts of Justice in London.

The 29-year-old father of six was gunned down after police stopped the taxi in which he was travelling in Tottenham, north London, in August 2011.

The resulting unrest in London and other cities left five people dead and caused millions of pounds worth of damage.

"We will still fight for justice," his brother Shaun Hall said outside the court, to chants of "No Justice" from other supporters.

The jury ruled that Mr Duggan did not have a gun in his hand when he was shot.

But they concluded that he had a gun with him in the taxi and threw the weapon over a fence seconds before the killing.

They also found that police had not done enough to gather and react to intelligence about the possibility of Mr Duggan collecting a gun from Kevin Hutchinson-Foster, who was jailed last year for supplying the gun.

After the jury recorded a verdict of lawful killing by an 8-2 majority, Mr Duggan's brother shouted obscenities at jurors as they left court while other supporters screamed "murderers".

Some smashed a door and security staff were called to contain the situation.

Inquests are heard in Britain after sudden or unexplained deaths.

The jury had a choice of three conclusions: lawfully killed, unlawfully killed or an open conclusion.

Judge Keith Cutler had earlier thanked the jury and told them that they would be excused from jury service - a legal obligation for adults in Britain - for the rest of their lives.

The riots sparked by Mr Duggan's death traumatised England, raising fears about security less than a year before the 2012 London Olympics and Queen Elizabeth II’s Diamond Jubilee celebrations marking 60 years on the throne.

Two days after Mr Duggan was killed, the deprived district of Tottenham erupted in violence, and the unrest then spread across the capital and on to Birmingham, Manchester and other English cities.

Hundreds of shops were looted, with many set alight, as groups of angry youths moved through the streets.

Dozens of people were jailed for offences related to the riots.

The inquest had heard evidence from a police marksman that he was acting in self-defence because he thought Mr Duggan was brandishing a gun.

The officer, identified only by the codename V53 during the proceedings, said that he fired twice at Mr Duggan.

The first shot hit him in the arm and failed to incapacitate him so he fired again, hitting Duggan in the chest.

The jury heard that a loaded gun wrapped in a dark sock was found several metres from the site of the shooting, but police found no weapon on his body.

Officers had strongly denied suggestions, raised during the inquest, that they might have planted the weapon at the scene.

Britain's Independent Police Complaints Commission is also investigating Mr Duggan's shooting.

In February 2013 drug dealer Hutchinson-Foster, 30, was jailed for 11 years in February for supplying Mr Duggan with the weapon, which was hidden in a shoe box.

Armed police in unmarked cars pulled over Mr Duggan's taxi 15 minutes after he collected the gun.

A judge said that Hutchinson-Foster could not be held responsible for the riots triggered by Mr Duggan's death.