This undated photo of William T Phillips was taken from the Larry Pointer Collection, American Heritage Center, University of Wyoming in Laramie, Wyo.

It is one of the most enduring stories to emerge from the American Wild West.

But the death of Butch Cassidy may not be quite as dramatic as we have been told.

A lost manuscript claims that the outlaw did not die in a gunfight in a shootout alongside his partner in Bolivia in 1908.

The scene was immortalised by Hollywood in 1969 Butch Cassidy and the Sundance Kid, with Paul Newman and Robert Redford running out into hail of bullets after being cornered by troops.

Instead, in a plot which could also have come straight out of a movie, Cassidy is said to have fled to France where he had surgery on his face before sneaking back into the US. Furthermore, according to the same account, he lived out his final days quietly and anonymously in Washington State and wrote an autobiography which he disguised as a biography.

American rare books expert Brent Ashworth and author Larry Pointer have obtained a 200-page manuscript from 1934 called Bandit Invincible: The Story of Butch Cassidy written by a William T Phillips which they claim was actually written by Cassidy.

They claim the book is Cassidy’s own story of his life as an outlaw.

It describes how after surviving the shootout in Bolivia he went to Paris and had his faced altered then went back to the US and reunited with an old girlfriend, Gertrude Livesay.

The authors say they married in Michigan in 1908 and moved to Spokane in Washington state in 1911. He apparently died in 1937, aged 71.

Its discovery is the latest of many theories surrounding the life and death of the two outlaws. It is also claimed by other writers that Sun-dance survived.

Cassidy was born Robert LeRoy Parker in 1866 in Utah, the oldest of 13 children in a Mormon family. He robbed his first bank in 1889 in Tellu-ride, Colorado, and fell in with cattle rustlers who hid out at The Hole in the Wall, a refuge in northern Wyoming s Johnson County. For 20 years, his Wild Bunch gang held up banks and trains across the West and in South America.

Despite the claims of Pointer and Ashworth, not all are convinced by the manuscript s authenticity.

Total horse pucky, said Cassidy historian Dan Buck. It doesn't t bear a great deal of relationship to Butch Cassidy s real life, or Butch Cassidy s life as we know it.

According to Hollywood, frontiersman Davy Crockett died fighting at the Alamo, cut down as he took on scores of Mexican soldiers. However, it is now suggested that Crockett tried to flee the final moments of the siege in 1836.

According to author Phillip Thomas Tucker, recently discovered Mexican accounts show the final battle in lasted as little at 20 minutes. In his book, Exodus from the Alamo, Tucker says the Mexicans surprised the Texan defenders as they slept and Crockett was executed after being captured. - AFP