Probe into deaths at Lister Surgicentre in Stevenage
Two patients died following routine surgery at a privately-run NHS clinic in Stevenage, an NHS trust has said.
NHS Hertfordshire said it began a probe into the Clinicenta-owned Lister Surgicentre following the fatalities which were described as "uncommon".
The clinic, which opened on the Lister Hospital site in November 2011, was criticised by the Care Quality Commission (CQC) in April.
Clinicenta said inquiries were standard practice after a patient death.
The centre provides routine surgery and treatment to NHS patients in areas such as ear, nose and throat, trauma, orthopaedics, general surgery, gynaecology and ophthalmology.
Services are commissioned directly by the Primary Care Trust (PCT), NHS Hertfordshire.
A trust spokesperson said: "We are treating these as serious incidents that need thorough investigation."
Dr Mark O'Flynn, from Clinicenta, said it took clinical safety "very seriously" and the two recent deaths were "very sad".
"Investigations are standard practice following a patient death to determine whether improvements can be made by any of the organisations involved in the care of a patient," he said.
"The patients were both transferred back to the local trust some days after their operations, so we are working closely with our NHS colleagues to carry out the investigation.
"Until this is concluded and the results made public, and out of respect for the families of the patients, it would be inappropriate for us to comment further at this point."
The PCT would not reveal when the deaths happened or what treatment had taken place, but the centre had already been told by the CQC that it "must take action", following an inspection in April.
A report published in September said service at the centre was "not meeting one or more essential standards" and criticised both a lack of staff and effective systems to identify and manage risks.
A spokesperson from NHS Hertfordshire said it would "continue to intensively monitor the management and delivery of services".