The Health and Safety Executive says it will take no further action after a patient suffered serious internal burns during an operation at a north Wales hospital.

Sixty seven-year-old cancer patient Mervyn Davies, from Dolgellau, underwent surgery at Wrexham Maelor Hospital to remove his voice box in September last year.

Patient Mervyn Davies: Died in December

But a flash fire affected the anaesthetic equipment causing serious internal burns.

Mr Davies died three months later from natural causes.

The HSE has now concluded the equipment involved was not faulty.

Hospital chiefs completed an internal inquiry into the explosion.

Following the operation, Mr Davies was kept in intensive care for four days and remained in hospital for seven weeks.

He was due to return to the hospital for a scan in January, but he died on 29 December at Dolgellau Community Hospital.

North Wales Corononer Dewi Pritchard Jones said a post-mortem examination showed Mr Davies had died of natural causes.

Burned fingers

An HSE spokeswoman said: "It was found that the piece of equipment was not faulty and what was concluded was that it was more to do with doctors' trainging.

"There are other bodies that can now better deal with the issue."

Bosses at Wrexham Maelor Hospital held an internal inquiry as a result of the incident and removed the instruments used in the operation from general use.

They found a small explosion took place 19 minutes into the operation.

Mr Davies's family claimed the surgeon conducting the operation burned his fingers in the incident.

It is also claimed that another surgeon was called upon to complete the operation, but because of the burns Mr Davies had received, it was not possible to do so.

Trust apology

NHS Trust officials apologised to his family at the time and his relatives praised the hospital for acting quickly to investigate.

After surgery, the retired forestry worker was admitted to the high dependency unit, although he was later transferred to the ear, nose and throat ward.

Following the emergency, Mr Davies was said to be depressed and afraid to finish the voice box procedure.

He is survived by his wife Pauline, two daughters, one son, two grandchildren, a brother and two sisters.

Mr Davies's funeral took place at St Marys Church in Dolgellau.