All the children affected were treated at the LRI

Dr Andrew Holton was suspended after he prescribed the wrong treatment to hundreds of patients in the late 1990s.

The General Medical Council launched an inquiry more than three years ago, but has still not set a date for a hearing.

A parents group says the case "should be given top priority rather than being pushed to the back of the queue".

'Little progress'

Trevor Parr of the Leicester Epilepsy Concerned Parents and Carers group said: "It is sad that after four years so little progress has been made."

Dr Holton was working as consultant neurologist at the Leicester Royal Infirmary in 2000 when he was investigated for misdiagnosing more than 600 children as epileptic and prescribed potentially damaging medication.

"The GMC is only dealing with 12 complainants out of the many hundreds that could have been presented," Mr Parr said.

"They have given us a series of dates but they appear to keep changing their minds and the dates."

The GMC declined to issue a statement as the inquiry is ongoing, but confirmed that no date has yet been set for the hearing.

Mr Parr said Dr Holton has been retrained and may be working again but his details are not on the GMC website.

A report by an independent NHS inquiry team in 2003 found complaints were first made about Dr Holton, who worked at the Leicester Royal Infirmary, almost three years before he was suspended.

Dr Holton was suspended on full pay in May 2001, but later left the University Hospitals of Leicester NHS Trust.