More than 40 years after his death, the King of Rock and Roll Elvis Presley is still inspiring conspiracy theories that he may not have actually left the building

A veteran policeman turned deceased rock star investigator has spoken of a mysterious photo that convinced him Elvis Presley is not dead.

When the King of Rock and Roll died while on the toilet of his Memphis home Graceland on August 16, 1977 he was just 42-years-old.

While his star had faded significantly over several years of intense over eating and drug use that, according to journalist Tony Scherman, made him into a "grotesque caricature of his sleek, energetic former self", his death proved simply unbelievable for some. 

Monte Nicholson, a veteran employee of the Los Angeles Sheriff's Department for 19 years, is one of them.

Soon after Elvis's death the retired cop was approached  by a man who claimed to have worked with the iconic singer.

Speaking on 1990 documentary The Elvis Files Monte described the 1977 encounter.

“One day, he showed up at work and had pictures of Elvis Presley getting in a helicopter which looked like a government helicopter," Monte said.

"There were men surrounding Elvis also getting into the helicopter who looked like what we often see depicted as government agents, with the blazers and the wire in their ear and what not.

"That pictured in itself was not particularly suspicious as it is common knowledge that Elvis himself was involved as an honorary police officer with many police agencies all over the country.

"The interesting thing, the curious thing about this pictured is that this individual claimed it was taken several hours after Elvis allegedly died."

Intrigued by the possibility Elvis faked his death, Monte contacted the man and asked to see the photos again.

He denied having them at first before changing his mind and asking for money to see the images.

Monte arranged a meeting with the mysterious contact and arrived at an arranged time and location, only to find an empty property with the man no where to be seen.

Despite the fact that neither man nor photos were ever seen again, and that his word was the only proof that the photos were taken after Elvis's death, Monte was inspired to write a book about the encounter.

The Presley Arrangement was published in 1987 and set out to prove the wild claims that Elvis was, in fact, still alive.