Johnny Hallyday has sold more than 100m albums
French rock star Johnny Hallyday has begun legal action against the surgeon who operated on his back last month.
The 66-year-old has been treated in hospital in Los Angeles to repair complications from surgery he underwent in Paris for a slipped disc.
He wants a board of independent medical experts to decide whether the operation was carried out correctly.
The singer has been forced to cancel the final leg of his concert tour in January and February.
Earlier this month, he was admitted to Cedars Sinai hospital after contracting an infection, allegedly during the back operation performed by surgeon Stephane Delajoux.
Doctors put him in an induced coma on Friday in order to conduct two operations.
Hallyday, who has been active since the 1960s, has a passionate following in the French-speaking world.
He has had a series of health problems since treatment for cancer of the colon earlier this year.
Controversy flared over the operation and Delajoux was beaten up on a Parisian street on Saturday.
The surgeon's lawyers insist there was "absolutely no negligence" during the operation.