Sussex Police launched Operation Bramber in May 2023 to investigate allegations of negligence at the hospital's general surgery and neurosurgery departments between 2015 and 2021. The probe is understood to cover over 100 cases, including at least 40 deaths.

A Sussex Police spokesperson said: ‘Cases relating to neurosurgery and general surgery at the Royal Sussex County Hospital in Brighton between 2015 and 2021 have started to be reviewed by specialist consultant surgeons who are totally independent of University Hospitals Sussex NHS Foundation Trust.

‘As a result of a further witness coming forward during the course of the investigation, police are now starting to review a small number of cases relating to cardiothoracic surgery at the Royal Sussex County Hospital. These enquiries are at an early stage, and officers are contacting relevant patients and families directly to provide information and support while this is ongoing.'

Professor Katie Urch, chief medical officer at University Hospitals Sussex NHS Trust, said: ‘We continue to co-operate fully with Sussex Police, and we will do everything we can to help their team to give families the clarity they need, as quickly as possible.

‘Safety is always our priority, and we remain absolutely committed to acting immediately on behalf of our patients, if the police investigation should ever raise any concerns about the standards of hospital services being delivered now.'

A letter sent to some families by the police seen by the BBC, stated: ‘From the cases assessed so far, the medical expert reviews have not revealed any evidence that would support a criminal investigation.'