The scientist who carried out the DNA analysis that identified Victorian-era serial killer "Jack the Ripper" as a Jewish barber named Aaron Kosminski has apparently made a fundamental error that fatally undermines his case, according to several top experts.

Scientist Jari Louhelainen is said to have put a decimal point in the wrong place when using a mitochondrial DNA (mtDNA) database to calculate the chances of a genetic match between DNA left on a shawl that allegedly belonged to one of Ripper's victims, Catherine Eddowes, and was supposedly discovered near her body, and DNA taken from descendants of Eddowes and Kosminski.

The apparent error, first noticed by amateur criminologists in Australia blogging on the casebook.org website, “has been highlighted by four experts with intimate knowledge of DNA analysis – including Professor Sir Alec Jeffreys, the inventor of genetic fingerprinting,” according to The Independent.

Professor Walther Parson of the Institute of Legal Medicine in Innsbruck has reportedly “echoed” Professor Jeffreys' concerns, as have Mannis van Oven, professor of forensic molecular biology at Rotterdam's Erasmus University, and Hansi Weissensteiner, also at Innsbruck and one of the scientists behind the computer algorithm used by Dr Louhelainen to search the mtDNA database.

Louhelainen used the database at the Institute of Legal Medicine to match a DNA fragment from the shawl with Karen Miller, the three-times great-granddaughter of Eddowes. Another DNA fragment was matched to a descendant of Kosminski's sister who asked not to be identified.

The error seems to have been made in the calculations linking Eddowes and Miller. If the critics are right, Louhelainen's calculations were wrong and virtually anyone could have left the DNA that he insisted came from Eddowes. This means that Eddowes cannot be connected to the shawl, and that therefore, no DNA connection can be made between Kosminski and Eddowes.

Case unsolved

Louhelainen had been hired by Russell Edwards, a businessman who bought the shawl in 2007 on the understanding that it was the same piece of cloth allegedly found next to Eddowes. Edwards published a book entitled Naming Jack the Ripper earlier this year.

"I've got the only piece of forensic evidence in the whole history of the case. I've spent 14 years working, and we have finally solved the mystery of who Jack the Ripper was. Only non-believers that want to perpetuate the myth will doubt. This is it now – we have unmasked him," he told The Mail on Sunday, which serialized the book.

Dr. Louhelainen reportedly declined to answer questions on the criticism of his work.

A spokesperson for publishers Sidgwick & Jackson said: "The author stands by his conclusions. We are investigating the reported error in scientific nomenclature. However, this does not change the DNA profiling match and the probability of the match calculated from the rest of the haplotype data. The conclusion reached in the book, that Aaron Kosminski was Jack the Ripper, relies on much more than this one figure."

Accoding to Metro, Edwards said he was partly inspired to take up the search after watching From Hell, a film about the Ripper murders starring Johnny Depp.