a doctor's promising career was in tatters last night after he was jailed for three months.

Michael McKenzie was convicted at Paisley Sheriff Court of supplying LSD to friends at a party last summer. During the two-day trial earlier this month, he denied giving the class A drug to friends last July. But Sheriff Neil Douglas found him guilty.

During the trial, the court heard how off-duty police constable Alexander Robertson suffered drug-crazed hallucinations after he took a ''tab'' of the drug at the party.

He heard howling like in the film American Werewolves in London and said ''everyone looked like zombies''.

He was suspended from duty and later resigned from the force after he reported himself to colleagues on the night the LSD trip turned badly wrong.

The ex-policeman told the court he had been ''given the acid'' by McKenzie while both were at the party with friends.

The former policeman said his experience had been nightmarish. Mr Robertson, 24, of Green Road, Foxbar, Paisley, said he had gone to the party last July knowing there would be drugs available.

After he was given the LSD by McKenzie, he suffered a bad reaction and went out looking for help. He returned to the party where his hallucinations became so bad he dialled 999 and reported he had overdosed.

Police went to the house at Alexandra Gate, Paisley, and he was taken to hospital for treatment.

When McKenzie returned to court for sentence yesterday, he was described as a dedicated and committed professional destined for an outstanding career.

He had earlier lined up a year-long contract to work at the Royal Alexandra Hospital, Paisley, but that had now fallen through.

He will now appear in front of the General Medical Council.

McKenzie, 25, worked at the Royal Maternity Hospital and Stobhill Hospital in Glasgow and the Royal Alexandra Hospital.

He recently took up a post as senior house officer specialising in obstetrics and gynaecology at Sunderland Royal Hospital.

Defence counsel Edgar Prais QC said he was highly regarded by senior staff at Sunderland and presented glowing references from a doctor who described him as a man of ''outstanding ability and professional excellence''.

The consultant, a Dr Rashid, said he had been filled with ''shock, surprise and incredulity'' when he learned of the convictions from newspaper reports three weeks ago.

Mr Prais said McKenzie had a lot to offer the community at large and although he still maintained his innocence, the conviction had ''shaken him to his boots, and his life to its roots''.

He had resigned from his position at Sunderland.

He said McKenzie had been an outstanding schoolboy and had unusually been offered a place at Glasgow University, aged 15. He had joined the Scouts and become a Scout leader before going to university.

McKenzie, of Hawkhead Road, Paisley, denied five charges of supplying the class A drug to others. At the close of the Crown case, two charges were dropped.

Giving evidence, McKenzie claimed he had only taken controlled substances once in his life - in 1996 when he went on holiday to Amsterdam.

He denied he had ever seen any of his friends involved in drug taking and refused to accept that any drugs - especially LSD - had been in circulation on the night of the party.

Finding McKenzie guilty, Sheriff Douglas said although it had been difficult to distinguish fact from fantasy as Mr Robertson recalled events, due to ''the terrible consequences of what happened to him'', he had no reason to disbelieve his account and concluded he was telling the truth.

Mr Prais urged the sheriff to consider alternative disposals to custody.

McKenzie, he said, would inevitably be hauled in front of the General Medical Council and his career would be hanging in the balance. He said he came from a good, respectable family who had suffered terribly due to the publicity the case had attracted.

Sheriff Douglas said he was prepared to restrict the sentence to three months on each of the three charges, to run concurrently.