The pivotal role of DNA fingerprinting in the Madeleine McCann investigation was brought further into question yesterday when the inventor of the forensic technique warned that it was insufficient to provide police with a firm conclusion.
Sir Alec Jeffreys, the scientist who discovered that fragments of genetic material could be used to identify individuals beyond statistical doubt, said he was willing to appear as an expert witness on behalf of Kate and Gerry McCann.
The geneticist and DNA expert would be a powerful advocate for the couple, not least because of his view on the ways that profiling should be used. He has spoken out against the use of a police-controlled, partial DNA databank, calling instead for a database with the DNA of every individual but controlled by an independent agency.
Sir Alec, 57, said the incomplete DNA fingerprint taken from the McCann's hire car, which is understood to be an 88 per cent match for Madeleine, could not be considered as categorically coming from the missing four-year-old.
He told BBC's Newsnight programme: "There are no genetic characters in Madeleine that are not found in at least one other member of the family. So then you have an incomplete DNA profile that could raise a potential problem in assigning a profile to Madeleine given that all other members of that family would have been in that car."
The scientist has described the discovery of DNA fingerprinting as "quite accidental".
Sir Alec was working at Leicester University in 1984 researching inherited illnesses by looking for DNA markers within family members. He realised from one experiment using small sections of DNA that the repeated patterns, unique to each individual, could be applied to a wide range of areas. The chances of two people having the same 20-number sequence are one billion to one.Reuse content