A 24-year-old man, from Huntingdon, has been arrested on suspicion of murder, two counts of attempted murder and possessing class A drugs with intent to supply.
A 20-year-old woman from Huntingdon has also been arrested on suspicion of murder, possessing class A drugs with intent to supply and possessing class B drugs with intent to supply.
Both were arrested this morning (September 16), and remain in custody at Thorpe Wood Police Station, in Peterborough.
The attempted murder offences relate to an incident in Huntingdon on October 5, last year, in which a car was allegedly driven at two people causing one of them serious injuries.
Robert Duquemin, 53, died at a property in Ringwood Close, Bury, on the morning of October 10.