The hat worn by Jack Ruby when he gunned down JFK's killer Lee Harvey Oswald on live television is set to sell for more than 21,000 pounds in an auction.

Nightclub owner Ruby was wearing the grey Fedora hat when he leapt out from a crowd of reporters and photographers and shot Oswald.

In the famous footage Oswald, who had assassinated the president in Dallas, Texas, two days before, can be seen doubling up as the pistol is plunged into his midriff.

Going under the hammer in the same auction is a copy of the Dallas Morning News signed by JFK just hours before his death, on November 22, 1963.

The autographed front page is believed to be the last signature ever given by President Kennedy before his assasination.

The newspaper, which JFK signed across a picture of himself for hotel maid Jan White, is likely to sell for more than 12,000 pounds.

Auction house Heritage Auctions describe the size 7 1/4 hat as 'a unique item from an unforgettable moment in American history.'

Ruby's name is embossed on inside of the sweatband in gold lettering, as is the seller, 'Jas. K. Wilson/Dallas' and the price of 16.50 dollars.

The hat is said to be in 'excellent condition' and is accompanied by a signed affidavit of authenticity from Ruby's brother Earl.

It also comes with photocopies of three pages from the Dallas County Probate Court Accounting of Independent Executor document identifying the hat as being the one worn by Ruby.

It is expected to sell for more than 21,000 dollars when it goes under the hammer on Saturday.

Also in the same auction is an X-ray taken of the right side of Ruby's head in the months before his first trial.

It is believed the X-ray, which could fetch over 600 pounds, was taken as Ruby's legal team considered a defence based on a condition called psychomotor epilepsy.

Interested parties can also bid on a set of 60inch long leg shackles used to secure Ruby's leg to his hospital bed to prevent abduction of his body in the event of his death.

The shackles are expected to sell for more than 3,000 pounds.

Oswald was being transferred from Dallas police headquarters to the nearby county jail when he was gunned down by Ruby.

Ruby, who was 52 years old at the time, struck before Oswald could reach the car which he was due to travel in.

The whole incident, on November 24, 1963, was captured on film making it one of the most iconic moments in American history.

Oswald died on the operating table in Dallas's Parkland Hospital - the same hospital JFK had died in two days earlier.

Ruby, who claimed he shot Oswald to avenge President Kennedy's death, was convicted of killing Oswald five months later.

He appealed the conviction and subsequent death sentence but died from lung cancer in 1967 before he could face the new trial.

Must credit pictures by: Solent News/Rex Features