SCIENTIFIC advances used in the Stephen Lawrence case could solve the mysteries of Madeleine McCann and Jill Dando.

Forensic experts working on the racist murder devised new techniques to discover microscopic clues that convicted two of the killers.

Now Scotland Yard hopes the same revolutionary approach could help find the truth behind the disappearance of three-year-old Madeleine in 2007 and the killing of BBC Crimewatch presenter Miss Dando in 1999.

The smallest speck of blood ever used in evidence at a British court nailed racist thug Gary Dobson yesterday.

Invisible to the naked eye, the minute spot was discovered on the collar of the bomber jacket worn by Dobson during the merciless gang attack on Stephen.

Two days of painstaking work with a microscope rewarded scientist Ed Jarman with the breakthrough in April 2008 – 15 years after the murder.

DNA tests proved it matched Stephen’s blood on the red polo top he was wearing, and the chances of it being anyone else’s was put at a billion to one. In April 1993 there was no chance such a tiny speck of blood, just 0.25mm by 0.5mm, could have produced a positive DNA result.

The “Start from Scratch” review into Stephen’s murder was ordered after the Forensic Science Service admitted major errors, including missed bloodstains, in the Damilola Taylor case.

The 10-year-old bled to death on a stairwell in Peckham, south London, in November 2000. Two teenagers were later jailed for manslaughter. Scientific advances that identified serial sex attacker Robert Napper as the killer of Rachel Nickell on Wimbledon Common also played a key role.

Clothing seized from Dobson and Norris, as well as other suspects, was sent to LGC Forensics – the firm which worked on the Taylor and Nickell cases.

Mr Jarman examined Dobson’s bomber jacket. LGC experts had already found blood flakes in the paper exhibit bag used to store the jacket. Using a microscope to increase the image size 40 times, Mr Jarman found the tiny speck.