A small pistol belonging to 1930s gangster John Dillinger has been sold at auction to a private collector for $US95,600 ($116,000) - more than double the pre-sale estimate.

Dennis Lowe of Heritage Auction Galleries said the Remington .41 calibre Double Derringer was said to have been found hidden in one of Dillinger's socks when he was arrested in Tucson, Arizona.

According to affidavits, Tucson's sheriff at the time gave the pistol to a probation officer, whose family kept it until selling it in 1959.

The owner, who wished to remain anonymous, sold it because he was in declining health, Lowe said.

It had been expected to fetch up to $US45,000 at the Dallas auction on Saturday (local time).

A private Los Angeles collector made the winning bid.

Dillinger was one of the most infamous bank robbers in the United States in the early 1930s.

He was shot dead by FBI agents in Chicago in July 1934, aged 31.

His exploits have inspired at least five movies or TV films including the most recent release, Public Enemies, in which Dillinger is portrayed by actor Johnny Depp.

- Reuters