Four people arrested over the murder of an aspiring lawyer have been released on police bail.

Sven Badzak, 22, was stabbed to death in a “completely unprovoked” attack by six young men as he went to buy a bagel in Kilburn, north west London on February 6.

The Metropolitan Police said on Tuesday that four suspects arrested in connection with the death had been bailed until late March.

They are two men aged 19 and 20, who were both arrested on suspicion of murder in the past two days, and two others aged 17 and 19 who were held on suspicion of murder earlier in the month.

Mr Badzak’s mother, Jasna Badzak, a former Conservative Party activist, said her son, who was privately educated at Wetherby and Portland Place schools before attending Roehampton University, had gone to a shop to get orange juice and then to a bagel shop when he was attacked.

The victim, from Maida Hill, west London, and his 16-year-old friend were chased and became separated, then Mr Badzak fell to the ground and was stabbed repeatedly.

The 16-year-old also suffered multiple stab injuries but managed to escape into a shop in Willesden Lane and was taken to hospital.

Anybody with information is urged to call police on 101 or tweet @MetCC quoting CAD 5580/06Feb or call Crimestoppers on 0800 555 111.