Two people have been re-arrested following the death of a man who was stabbed days before Christmas.
Daniel Saunders, 32, died on 16 December after being stabbed in the abdomen in Turin Street, Ipswich.
A 33-year-old man from Colchester and a 15-year-old boy originally from Bury St Edmunds were re-arrested on suspicion of being concerned in supplying a controlled drug, and later released.
A 17-year-old boy from Bury St Edmunds has already been charged with murder.
The 15-year-old boy, who now lives in west London, was initially arrested on 20 December while the 33-year-old was first taken into custody on 29 January.
Three males from Colchester, aged 17, 18 and 20, remain under investigation alongside a 44-year-old man from Ipswich.
Police also renewed their appeal to trace the female driver of a people-carrier with a sliding door who may have "valuable information".
The woman, who is described as being in her 30s or 40s and speaking with a local accent, stopped to help Mr Saunders at the scene.
The boy charged with murder has been remanded in custody until his next hearing on 12 April.