A man shot dead in front of his family on Christmas Eve had contacts with Sweden’s gang world, authorities have confirmed, as details of the victim’s criminal connections emerged.

Flamur “Alex” Beqiri, 36, was shot outside his home in Battersea, south-west London, at about 9pm on 24 December as he returned with his wife and young child. The attacker fled on foot, police said.

Beqiri, a Swedish national born in Albania, had been living in London for four or five years, according to Scotland Yard.

As speculation mounted surrounding a possible revenge motive for the gangland-style killing, Sweden’s prosecution service confirmed that Beqiri was friends with the boyfriend of Karolin Hakim, who was gunned down in Malmö in August when the pair were walking with their baby in broad daylight.

When two gunmen approached, the boyfriend fled, but Hakim was shot in the head and died at the scene. Reports say the killers had targeted her boyfriend.

The murder of Hakim, who had recently qualified as a doctor, shocked Sweden and led to a renewed focus on violent gang feuds in the country.

“What is very striking is that [Beqiri] was shot dead when he was with his wife and child in the same way that Hakim was shot dead while holding her child,” prosecutor Pär Andersson, who is leading the investigation into Hakim’s death, told Swedish media on Friday evening.

“It is so ruthless to murder people in front of their family and children.”

The link with Hakim’s boyfriend is one of several that Scotland Yard is now investigating with the cooperation of Malmö police.

“We believe Flamur may possibly have been involved in some criminality in Sweden, and are in liaison with our Swedish counterparts to try to understand what, if any, incidents there may have been that might have led to someone seeking retribution against Flamur in the UK,” Det Insp Jamie Stevenson said in London on Friday.

Separately, the Guardian can reveal that Beqiri was connected to a convicted gun runner serving a jail sentence in Sweden for trying to sell pistols and shotguns that he had smuggled into the country.

Tamer Zahran was jailed in 2017 for four years and five months for his part in smuggling 235 weapons from Slovakia. The 4,100-page indictment from Malmö district court includes photographs displayed on Zahran’s Facebook page. Zahran is included among Beqiri’s Facebook friends.

Beqiri was briefly the subject of a nationwide manhunt in Sweden in 2007 after 340kg of cannabis was seized in Malmö. He allegedly fled barefoot from police, and was later fined and given a suspended sentence, but cleared of drugs charges.

He maintained friendly contacts with several people in southern Sweden’s gang world, Swedish police said on Friday, although he had faced no criminal charges for more than a decade.

Beqiri left Sweden for the UK after receiving death threats, Swedish media reported. In London he established a music company and apparently tried to start a new life. He and his wife, Debora, were married in October 2018 at a lavish wedding ceremony on Lake Como.

Beqiri’s neighbours in Battersea said they heard between eight and 10 shots fired in quick succession, followed by his wife’s screams for help. No arrests have been made and the Metropolitan police have appealed for witnesses to come forward.

Beqiri was the brother of Missé Beqiri, the star of reality show Real Housewives of Cheshire.

In a statement released through Scotland Yard on Saturday, Beqiri’s family spoke of their grief: “We thank everyone for their kind thoughts and condolences.

“Our family are in a state of shock and are grieving. To have so much sadness at this time of the year is heartbreaking.

“We would kindly ask that you respect our privacy and let us grieve in peace.”