A mother was cleared of murdering her four-month-old son yesterday at a retrial that was ordered after discredited paediatrician Professor Sir Roy Meadow gave evidence at the original hearing.

Epilepsy sufferer Margaret Smith, 39, who stabbed her first husband to death, collapsed in court after a jury found her not guilty of smothering her baby son, Keith, at their home in St John's Grove, Hull, in September 1994.

A jury at Newcastle Crown Court was not told during the eight-day hearing that this was a retrial.

The mother of nine had been convicted of Keith's murder in 2002, but cleared of killing her five-and-a-half month daughter Kelly, who died in 1992.

Her defence team won an appeal after showing Prof Meadow's evidence at the original trial at Leeds Crown Court was "prejudicial" and should have been inadmissible.

Mrs Smith, from a family of travellers originally from Ayrshire, Scotland, was accused by a child witness of smothering Keith.

The girl, aged seven at the time, claimed she saw Smith put a pillow over his face to stop him crying.

But the jury heard there were "inconsistencies" in the girl's account and after she claimed she was away from school on the day Keith died, a school register was provided that showed she was present.

A post-mortem examination showed cot death was the most likely cause of death, just as had happened two years previously with Kelly.

The jury was not told that Mrs Smith and her second husband were jailed for six years for stabbing her first husband to death in 1995.

Robert (Jock) Brannan, 53, was discovered in his bath with 51 stab wounds.

The couple blamed each other and were cleared of murder at York Crown Court but jailed for six years for manslaughter.