The Royal National Orthopaedic Hospital said most removals had "valid reasons" but it had to take any allegations lists had been manipulated very seriously.

Stuart Coalwood, acting director of commissioning, has been suspended.

Waiting lists are a key part of a hospital's performance rating, which is linked to its funding.

If the investigation finds any patient has been taken off the list inappropriately, we will take immediate steps to offer them an early operation Hospital statement

The hospital trust said an investigation into "possible irregularities" had begun after concerns were raised by a member of staff in May.

In a statement, the trust said: "This investigation is now concentrating on the specific cases and why each patient was removed from the list.

"We expect that most of these 300 patients have been taken off the waiting list for valid and legitimate reasons.

"However, if the investigation finds that any patient has been taken off the list inappropriately, we will take immediate steps to offer them an early operation."

The hospital is a national leader in musculoskeletal health care - treating everything from bone tumours and spinal injuries to chronic back pain.

Patients are referred to its specialist consultants from all over the country.

The Duke of York's daughter, Princess Eugenie, had an operation to correct a curvature of the spine there in October 2002.

Trust chief executive Andrew Woodhead said the hospital was committed to offering patients procedures and operations as quickly as possible.

He added: "We take any allegation that waiting lists are being manipulated extremely seriously."