Disgraced gynaecologist Richard Neale has been arrested as part of a long-running police investigation.
Neale was struck off in 2000 for serious professional misconduct
Mr Neale was struck off in 2000 after complaints of botched operations were upheld by the General Medical Council.
The operations were mainly carried out at Friarage Hospital in Northallerton, North Yorkshire.
Police will not reveal the nature of the inquiry, but said a 59-year-old man from Boroughbridge, North Yorkshire, had been arrested and bailed.
Richard Neale got a job at Friarage Hospital, despite having been struck off by the Canadian authorities in 1985 after an investigation into the deaths of two of his patients.
He was struck off in the UK in 2000 after being found guilty of serious professional misconduct.
During a previous criminal inquiry, the Crown Prosecution Service (CPS) looked at five cases to see if there was enough evidence to support charges of criminal recklessness or assault.
But in 2001, the CPS decided there was "no realistic prospect" of a conviction.
In August 2004, after the independent inquiry ordered by the government into the Neale case was published, North Yorkshire Police announced they were reopening the investigation.
As well as working in Northallerton, Mr Neale also had spells in Leicester and at the exclusive Portland Hospital in central London.