Dr Lam started the operation in St Teresa's Hospital, Kowloon City, on June 18 last year, but aborted it after an hour when excessive bleeding around the tumour made it too dangerous to continue. Wang died a month later of cancer in Queen Elizabeth Hospital.

Dr Lam is accused of performing an inappropriate operation.

'Dr Lam said it was only with confidence that he would ask the family member to agree to the operation,' Ms Chow, 44, told the council.

'Having heard that, my mother agreed because all along she had faith in what Dr Lam said.' Ms Chow said her mother was not in pain before the operation.

Afterwards, however, she was bedridden and in pain caused by the surgical wound, which was more than 15cm long.

Expert witness Dr Wong Kwok-kee, a surgeon and urologist, said Dr Lam's preparation for surgery fell well short of accepted medical standards.

He said Dr Lam should have anticipated the bleeding and avoided it by cutting into the woman's abdomen rather than her side, sealing off blood vessels as he went.

He said the size of the cancer meant a heart-lung bypass operation could have been necessary, so experts in that field should have been on hand and the family should have been told that major surgery was being attempted.

While the vessels around the tumour that ruptured during surgery had not shown up on a scan taken two days before the operation, Dr Wong said Dr Lam should have known they would be there.

In his defence, Dr Lam, a general surgeon since the mid-1970s, said he never intended trying to remove all the cancer.

He said removing the bulk of it would have eased the burden the growth placed on Wang's body, and the pain he said she reported, without going near her heart.

But 500ml of blood was lost in half an hour from blood vessels he said he could not have expected to see, so he stopped the bleeding and sealed the wound without completing the surgery.

An expert witness called by the defence, emeritus University of Hong Kong professor Ong Guan-bee, said he would have proceeded as Dr Lam had.

He said that had Dr Lam intended to remove the whole tumour he should have gone in from Wang's front, but that for what was planned, side entry was ideal.

Asked whether Dr Lam was competent to deal with Wang's condition, Professor Ong said: 'He has removed livers, lungs - why shouldn't he be able to do it?' After nine hours of hearing evidence, the council last night adjourned the matter to a date yet to be set.

Dr Lam practises from the Hang Seng Mongkok Building, Nathan Road.