Police have confirmed they are no longer treating the death of a woman in Thetford as suspicious.

It follows a Home Office post mortem examination which, while proving inconclusive in relation to the cause of death, revealed no primary evidence of traumatic injuries.

Consequently, the enquiry is now being treated as a sudden death and five people arrested on suspicion of murder have been released without charge.

However, another four people have been arrested in connection with the incident on suspicion of supplying Class A drugs.

Officers were initially called to a property in Frobisher Close just after 5.30pm on Monday after the ambulance service already in attendance raised concerns. A woman in her 40s was pronounced dead at the scene.

Detective Chief Inspector Marie James, from the Norfolk and Suffolk major investigation team, said: 'Following the results of the post mortem and our initial enquiries, I am satisfied there was no third party involvement in the woman's death.

'Further investigation will now take place to ascertain a cause of death and a file will be prepared for the coroner in due course.'

On Wednesday afternoon police arrested a further four people, two men and two women aged between 30 and 41, in connection with the incident.

The suspects have been arrested on suspicion of supplying Class A drugs and robbery after they were found in possession of suspected stolen property.

All suspects remain in custody at Wymondham Police investigation Centre where they will be questioned.

Officers are also investigating the circumstances surrounding the death of a man in Durham Way, Thetford on Monday.