THREE people have been arrested as a murder investigation was launched following the death of a married couple.

Respected business pair Stephen and Carol Baxter were found unresponsive by a family member in their home in Victory Road, West Mersea, on Easter Sunday.

Their deaths were initially treated as unexpected but not suspicious.

However, an inquest held in Chelmsford this morning was told they had the drug fentanyl in their systems.

A post-mortem examination was carried out at Broomfield Hospital which gave a provisional cause of death for Mrs Baxter, 64, as combined fentanyl and promethazine toxicity with terminal bronchopneumonia.

The provisional cause of death for Mr Baxter, 61, was delivered as cardiomegaly and alcoholic liver disease with fentanyl intoxication.

Fentanyl is a powerful synthetic opioid which is similar to morphine but up to 100 times more potent.

It is a prescription drug which is also made and used illegally.

Gazette: Emergency - police officers and paramedics attended the Baxter's home address in Victory RoadEmergency - police officers and paramedics attended the Baxter's home address in Victory Road (Image: Google)

Essex Police has now said three people have been arrested on suspicion of murder as part of an investigation into the deaths.

A spokesman said: "As a result of an extensive investigation and toxicology analysis, two men and a woman were arrested in order to gain comprehensive accounts from them.

"They remain in custody for questioning as other inquiries are conducted.

"We continue to remain open-minded as to how the couple died."

Gazette: Hearing - individual inquests into the deaths of Carol and Stephen Baxter were opened at Essex Coroner's CourtHearing - individual inquests into the deaths of Carol and Stephen Baxter were opened at Essex Coroner's Court (Image: Archant)

Paramedics were called to the address on April 9 but the couple, who were joint directors of bath and shower mat firm Cazsplash, were confirmed dead at the scene.

Inquests into the couple’s deaths were opened individually at Essex Coroner’s Court in Chelmsford this morning.

Area coroner Sean Horstead said: “On the basis of the information I am satisfied that this requires a full inquest.

“At the written request of Essex Police, I will suspend the coronial investigation for four months.

Gazette: Yachting - the Baxters were keen members of West Mersea Yacht ClubYachting - the Baxters were keen members of West Mersea Yacht Club (Image: Google)

“That will run until November 6. No doubt there will be communication from Essex Police from the expiry of that date.

“I offer my sincere condolences to the friends and family of [the Baxters] during this very difficult time for them.”

Mr and Mrs Baxter were both keen members of West Mersea Yacht Club, in Coast Road, which flew its flag at half mast following their deaths as a mark of respect.