Two doctors accused of covering up a massive morphine overdose given to a premature baby were found not guilty of serious professional misconduct by the General Medical Council, yesterday.

Twin Louise Wood was just one day old when she received a morphine dose that was 100 times the intended amount at Rotherham District General Hospital, on October 1, 1995. Within an hour of the two injections, she was dead.

Registrar Dr Vivian Michel, 45, of Southwick, Peterborough, administered the fatal dose.

Consultant paediatrician Dr Jean Shorland, whose job was to monitor drug dosages, instructed him to complete a ''potentially misleading'' death certificate which made no mention of the overdose, the council's professional conduct committee was told.

She also should have immediately informed the coroner about the death, the committee found.

Announcing the decision, conduct committee chairman Sir Herbert Duthie told both doctors: ''Taking all relevant matters into consideration, the committee has adjudged you to be not guilty of serious professional misconduct.''

Louise's grandmother, Mrs Dorothy Wood, said at her Rotherham home, yesterday, that the family was ''disgusted and distressed'' by the decision.

''We are all very, very upset.

''It was upsetting when it happened. It was upsetting at the inquest and it brought it all up again now, and we feel it was for nothing.''

An inquest in February 1997, recorded an open verdict on Louise's death, but criticised Dr Hilary Evans over her mathematical skills.

After yesterday's hearing, Dr Michel said: ''This has been a very long and distressing time for everyone involved, especially Louise's family, and I realise that the matter has been fully investigated. I'm very pleased with the decision that the GMC has reached today.''

Earlier, the committee had found that Dr Shorland should have known the morphine overdose was a possible cause of death to the baby born seven weeks prematurely.

As such, she should not have ordered Dr Michel to complete the death certificate and she should have immediately informed the coroner. Dr Shorland reported it two days after Louise's death, when she realised there was cause for concern.

Dr Michel was found to have completed the death certificate, which made no mention of the morphine overdose. Allegations by nurses that they had warned him the dose was excessive were found unproven.

The morphine was supposed to sedate the 1.5 kilogram baby, who was suffering breathing problems, so that a chest drain tube could be inserted.

It was drawn up by junior doctor Hilary Evans, who made an error in calculation and placed a decimal point in the wrong place.

The dosage should have been checked before being administered but it was not, the GMC heard.

Dr Evans, 29, of Bromsgrove, Worcestershire, was found not guilty of serious professional misconduct on Tuesday.

Dr Michel earlier told the hearing that he regretted failing to double check the calculations and apologised to Louise's parents for not ensuring the coroner was informed.

Dr Shorland admitted to making ''a grave error of judgment'' in not referring the case to the coroner. Her heartfelt belief had been that Louise's death was caused by respiratory problems.