A recently surfaced letter allegedly written by one of the escapees of Alcatraz prison in 1962, suggested all three prison escapees might have survived after making the daring escape from the highly secured prison. 

According to a report by KPIX, a CBS-affiliated television station, the letter was exclusively obtained by the station from an un-named source. 

The letter said: "My name is John Anglin. I escape from Alcatraz in June 1962 with my brother Clarence and Frank Morris. I’m 83 years old and in bad shape. I have cancer. Yes we all made it that night but barely!"

The letter was sent in 2013 to the San Francisco Police Department’s Richmond station, the report stated.

According to the Federal Bureau of Investigation (FBI), the letter which was being treated as a new piece of evidence, resulted in the law enforcement agency reopening the cold case. 

Jeff Harp, security analyst of KPIX said: "It’s interesting, I mean it’s obviously a very famous case here in San Francisco."

"As a law enforcement person I’d like to think that their escape attempt was not fruitful for them," Harp said. "Personally, as someone who swims in the bay, and we have a triathlon that goes on every year, and there’s not a single person that doesn’t make that swim."

Harp spent 21 years working for the FBI, but he did not work directly on the case of the famous Alcatraz prison escape. 

The United States Marshals Service, in a written statement, said: "There is absolutely no reason to believe that any of them would have changed their lifestyle and became completely law abiding citizens after this escape."

National Park Service Ranger John Cantwell said: "The Federal Bureau of Prisons say that they drowned once they got off of Alcatraz and their bodies were swept out to the Pacific Ocean — end of story."

The report stated that if the escapees are alive, then Frank Morris would be 90 years old, while John and Clarence Anglin would be 86 and 87 respectively.

Author Jolene Babyak who stayed on the island when the escape took place said: "I didn’t believe that they made it, but that was because of what the officers were saying." Babyak’s father was the acting warden of the prison at that time.

"I was awaken by the siren, which I had never heard before, so I wasn’t really sure exactly what it was," she said. "No evidence, lots of allegations, no real evidence, nothing you can follow up on."

"They’re getting up there in age, someone knows, cause if they made it out they communicated with somebody, so somebody somewhere knows — that’s still alive," Harp said.

However, the U.S. Marshals perceived this lead to be closed and also didn’t give it any merit.

The Alcatraz prison escape is one of America’s greatest mysteries. The three men made a brave prison escape from Alcatraz in 1962 which was one of the most heavily guarded and secured prisons in the U.S. The prison is surrounded by the rough Pacific waters.

The escape resulted in Morris, John and Clarence Anglin becoming a part of American folklore. Their stories were made into movies and television shows.