Family members and residents of a care home where three people died of suspected carbon monoxide poisoning previously told inspectors that staff were “very safety conscious”, according to reports from the health watchdog.

Dorset Police received a report at 7.16am on Wednesday of three residents – two men, aged 74 and 91, and an 86-year-old woman – who were found dead at Gainsborough Care Home in Ulwell Road, Swanage.

Seven people were taken to hospital as a precaution and were not in serious condition, the force said.

Other residents at the address have been evacuated and have been moved to other homes until they can be returned to the Swanage care home.

The deaths are being treated as unexplained and detectives are still exploring possible carbon monoxide poisoning as the main line of inquiry. There is no wider risk to the community, the force said.

A 60-year-old woman, arrested on suspicion of manslaughter, has been released under investigation.

The care home had its last full inspection by the Care Quality Commission (CQC) in 2019, when it was rated as requiring improvements for safety and well led by concerns that unsecured furniture could be dangerous.

Following a focused inspection in October 2021, inspectors upgraded the care home for both categories to good.

In its report published the following month, the CQC said: “People told us they felt safe at Gainsborough Care Home.

“Two people confirmed: ‘I feel safe because there is always someone around’ and ‘I feel very safe in this house.’

“Relatives also expressed confidence that their family members were kept safe. Comments included: “We are sure (name) is safe” and “They are very safety conscious.”

The report also states that residents have personalized risk assessments that are up to date.

It states: “Risks from the fire to people have been reduced to a minimum. Fire safety records recorded regular fire drills, equipment tests and maintenance.

“In addition, people had personalized evacuation plans detailing how they should be supported in the event of a fire.”

It added: “At the previous inspection the home demonstrated improvements in risk management to the safety of people from unsecured furniture and auditing to identify and manage risk.

“At this inspection, we found that improving evidence in this area was supported and people were safe.

“The registered manager brought stability to the home and greater managerial oversight.

“People, relatives, staff and professionals were unanimous in their praise for the registered manager, who saw them as proactive, responsive and keen to encourage everyone to contribute ideas to drive further improvements.

“People felt safe and lived happily at Gainsborough Care Home.”

Following a previous inspection in November 2020, a CQC report states: “Since the previous inspection, the provider has made improvements to quality assurance systems in the home to include the security of furniture in people’s rooms.

“The registered manager said, ‘People here are definitely safer now.’

After an inspection in September 2020, the CQC states in its report that there was a “period of managerial instability at the home”, but a new manager and deputy started in March 2020.

A spokesman for Gainsborough Care Home said in a statement released on Thursday: “We are deeply saddened that three residents who lived at our care home died yesterday.

“Our sincere condolences remain with their families and friends during this distressing and difficult time.

“We are cooperating fully with the lead agencies as the investigation into what happened continues.

“Our priority has been to work with Dorset Council and BCP Council to safely move residents to other care homes until we are informed they can return home.”

The statement continued: “We ensure that those directly affected are supported and kept up to date with changing circumstances, with the necessary information and reassurance provided.

“We would like to thank our care teams for their work in managing the situation and looking after residents during such a difficult time.

“We are also grateful for the kind messages received and practical support from partner public sector agencies, the local community and other social care providers.

“The home has long been an essential part of the Swanage community and our residents, families and team members are all affected by this tragic incident and touched by the outpouring of support.”