A mummified hand and arm found in an Alaska glacier nine years ago have been identified, after nearly a decade of forensic detective work using the most advanced DNA techniques.

The limb belongs to Francis Joseph Van Zandt, a 36 year old merchant marine from Roanoke, Virginia in the US, who had been on an airplane rumoured to contain a large amount of gold when it smashed into the side of an Alaskan mountain in 1948. Thirty people died in the crash of Northwest Airlines flight 4422.

"This is the oldest identification of fingerprints by post-mortem remains," said latent fingerprint expert Mike Grimm, at a press conference to reveal the discovery.

Twenty-four merchant marines and six crewmen died in the crash on March 12, 1948. They had just sailed a loaded oil tanker, the SS Sunset from Bahrain to Shanghai and were now on their way back to New York. Shortly after leaving Anchorage the chartered plane flew into the side of Mount Sanford, possibly because the pilots were blinded by an unusually intense aurora borealis that night. According to police reports from the time it struck a cliff face 11, 000 feet up the 16,000 foot mountain, burst into flames and fell 3000 feet down the mountainside, eventually landing in an area so inhospitable that even the locals avoided the area. The wreckage disappeared into the glacier within a few days.

An air search spotted the wreckage but officials decided there was no chance of survivors. However the rumours that the plane carried Chinese gold continued, mainly because the marines had just delivered the oil tanker to Shanghai. No gold has ever been found but the two retired US airforce pilots who discovered the wreckage in 1999 found that they had set off on a sci-fi adventure of high-tech detective work using advanced DNA science and the most cutting edge forensice techniques.

Kevin McGregor and Marc Millican had already spent five years trying to find the plane, intrigued at the stories of the mysterious cargo of gold. In 1994 they had hiked 16 miles through the inhospitable terrain, but failed to reach the site and the following year although they got to their destination, they found nothing. In 1997 they discovered a piece of metal with the serial number of one of the engines and eventually, two years later, found the arm partly buried in gravel and mould.

The remains were flown to Anchorage where the Alaskan State medical examiner took inked prints. The remains were then embalmed.

The Alaska Department of Public Safety tried to match the fingerprints to numerous databases but came up with nothing because the limb had been frozen and dehydrated for so long that the details of the fingerprints were unclear. A few pieces of the arm were sent to a commercial DNA laboratory but no data could be obtained from that, either.

In 2006 Dr. Odile Loreille at the Armed Forces DNA Identification Laboratory in Rockville, Maryland, who expertise is in extracting DNA from the embalmed remains of unidentified soldiers from the Korean War, was asked to help. Dr Loreille developed new methods that allowed her to read the hand and arm's mitochondrial DNA - that is, DNA passed down by females. The team then approached forensic genealogist Dr. Colleen Fitzpatrick to help them in the search for living relatives of the victims. She and her assistants found family members of 16 of the victims, but still no DNA matches.

In the meantime, Mr Grimm, working with Edward Robinson, a professor of forensic science at George Washington University managed to get a complete set of fully legible fingerprints by using a newly-developed rehydrating solution.

On Sept. 6, 2007, the prints were compared with some kept at the National Marine Center in Arlington, Virginia, and a match was found. The DNA was also matched - to that of a distant cousin of Mr Van Zandt, Maurice Conway, who lives in western Ireland.

"I had mixed feelings, but I was delighted to be part of this project," Mr Conway said by phone from western Ireland to the press conference. "I learned a lot about my own family, but I felt like I was walking, sleeping and talking with the dead."

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