Ms Dyer was thought to have been ''Boulder Jane Doe'' - a woman found beaten to death possibly at the hands of Harvey Glatman, the so called ''Lonely Hearts Killer''.

But carers for an 84-year-old woman in Queensland made a chance discovery identifying her as the suspected dead woman, leaving police in the US ''back to square one'' over the unresolved murder.

The unidentified body of ''Boulder Jane Doe'' was found beaten to death near Boulder, Colorado, in 1954. Animals had left her face unrecognisable, but police have long believed the woman to be Ms Dyer, a woman who disappeared at around the same time.
Some believe she may have been an early victim of Glatman, who terrorised women in the 1950s, eventually being convicted and executed over three murders.

But on Thursday, the Boulder County Sheriff's office conceded that the most likely candidate for the murder was in fact alive.

It follows events in Queensland a week earlier. Carers preparing to move the woman they knew as Barbara into a care home stumbled across an address book belonging to Katherine Farrand Dyer.

A quick internet search linked her to the suspected murder victim. Further research put them in contact with Silvia Pettem, the author of a book on the Boulder Jane Doe case. The writer tracked down relatives of Ms Dyer who fleshed out the details of how she came to be living in Australia.

According to the woman's siblings she left Denver for personal reasons, moving to California and Hawaii before emigrating in 1963. Police in Boulder described the discovery as a ''good news, bad news'' development.

The investigation into Boulder Jane Doe's murder was reopened in February 2004, but with the most likely candidate for the murder victim now ruled out, officers face the uneviable task of looking for a new contender.

Phil West, operations division chief at Boulder County Sheriff's office, said: ''While it's a relief to know that Katharine is alive, it's also discouraging in that we are back to square one with essentially no viable candidates for who 'Jane Doe' might be.''