Berlin truck attacker Anis Amri was a habitual user of cocaine and marijuana, according to an autopsy report by Italian authorities.

Tunisian national Amri drove a truck into crowds at a Christmas market in the German capital on 19 December, killing 12 and injuring 56. In a video released after the attack he pledged allegiance to Isis leader Abu Bakr al-Baghdadi.

He was shot dead by police in Milan days after the attack, fleeing an international manhunt.

Italian investigators said that though it was unlikely that he had consumed drugs on the day he was killed, they could not rule out the possibility he had done so on the day of the attack, Italian news agency Ansa reported.

Traces found in Amri's body found that he had habitually taken cocaine and marijuana, according to an autopsy report.

Amri arrived in Italy in 2011 on a refugee raft, and was jailed for two years in the country for torching a refugee centre. He travelled to Germany on his release, and according to German media reports fell in with radical preacher Abu Walaa, who has been arrested for recruiting for Isis.

He was placed under police surveillance, and was found to be working as a drug dealer in Berlin's Görlitzer Park, though authorities did not have sufficient evidence to arrest him on suspicion of terror offences.

He had been due to be deported after his refugee application failed ahead of the attack.