A MURDER charge GP was justified in administering high doses of the painkiller morphine to three of his patients who were already dying, a court was told.

Dr Howard Martin was said to have not acted unreasonably in the circumstances by an expert defence witness in his trial at Teesside Crown Court.

Karol Sikora, a professor of cancer medicine at the Imperial College School of Medicine, at London's Hammersmith Hospital, was repeatedly pressed over the levels of the drug used by Dr Martin and said in similar circumstances he may have done the same thing.

Dr Martin, 71, a now retired former County Durham GP, denies killing 74 year-old cancer sufferer Harry Gittins, of Newton Aycliffe, by administering a lethal dose of morphine.

He has also pleaded not guilty to the same charges in relation to Frank Moss, 59, of Eldon, Bishop Auckland, who had lung cancer, and Stanley Weldon, 74, of Coundon Grange, who suffered from Alzheimer's disease.

Yesterday, Prof Sikora said that symptoms displayed by Mr Moss days before his death on March 14, 2003, namely bad hiccups and belching, were indicative of what he called the common onset of the terminal phase of lung cancer with the tumour having entered the diaphragm.

He conceded that two doses of morphine given to Mr Moss were at the high end of the scale, but said they were not necessarily unreasonable.

The second, administered while he was already unconscious, was justified in order to make sure the patient made it through the night peacefully and did not wake up suffocating and suffering distress and anxiety.

Prof Sikora said Harry Gittins was suffering from a large tumour in his oesophagus and would have been in considerable pain.

Again he agreed that the doses of morphine given to Mr Gittins on January 21, last year, the day before his death, were high, but not unreasonable, given the clinical circumstances.

Asked what he thought his life expectation because of the cancer was on this day, he replied: "Less than 24 hours."

Later, Prof Sikora clashed with prosecutor Robert Smith, who said he was "out on a limb" with his views.

Mr Smith said a 60mg dose of morphine given by Dr Martin to the third victim, Stanley Wheldon, posed a very real risk that it would kill the patient.

Prof Sikora, who said Dr Martin was attempting to relieve the suffering of Mr Wheldon, replied: "If the patient is dying, there is no risk at all."

The trial of Dr Martin, of Gwynedd, North Wales, continues.