AT least 35 patients have had the wrong part of their body operated on in the past five years, new figures reveal.

Errors include one patient having a needle thrust into the wrong side of their chest during an emergency procedure and several patients having the wrong part of their head operated on.

Patients' groups have hit out at the string of mistakes, saying it was both a tragedy and frightening such mistakes could happen.

Patients are visited by consultant surgeons and anaesthetists before operations and it is standard practice for medics to "draw" on the operation site before the patient goes into theatre.

The details of botched surgeries follow the revelation last month that the Scottish NHS spent more than £186 million on compensation in the past five years.

Four out of Scotland's 14 health boards admitted to operating on the wrong body parts. NHS Greater Glasgow and Clyde admitted there had been 12 occasions in which staff had mistakenly operated on the wrong part of the body. Three involved operations on the head.

A document, released through the Freedom of Information Act, stated the patient's head had been "shaved, prepped, incision made and with the skin open a small amount of dissection was carried out on right side" when it should have been on the left.

NHS Lanarkshire said there had been two occasions when their staff had carried out procedures on the wrong part of the body. Both involved patients being treated for "squints" and they were given "injections to the wrong muscle" in their eye.

NHS Tayside revealed it had 20 incidents in which staff had incorrectly carried out operations or procedures on the wrong part of their body.

NHS Lothian admitted to "five or fewer" errors but refused to give details, claiming patients could be identified. Fife said it did not hold the details. The other boards said there had been no mistakes.

Jean Turner, executive director of Scotland Patients Association said: "The tragedy is that these are not just statistics, but people this has happened to."

A Scottish Government spokeswoman said: "While any surgical error is regrettable, it is important to put these figures in context as they reflect a tiny number of the 1.2 million procedures carried out safely each year.

"We have witnessed a 23 per cent reduction in surgical mortality since 2008, have implemented the World Health Organisation surgical checklist and are committed to further improvements."