The only known colour film of Sir Donald Bradman playing cricket has been discovered in a gift to the National Film and Sound Archive of Australia (NFSA) and the donor had no idea what he had.

Key points: The footage shows Bradman batting in his second-last first-class innings, in 1949

The footage shows Bradman batting in his second-last first-class innings, in 1949 It came a year after his famous final Test dismissal

It came a year after his famous final Test dismissal The man who donated the film had "no idea" what was on it

The film was shot in February 1949 as Sir Donald Bradman played his second-last first-class innings in a testimonial match for two of his old New South Wales captains, Alan Kippax and Bert Oldfield, at the SCG.

He was 40 years old and had been recently knighted.

The bright colour footage shows him striding to the crease in front of a packed crowd of more than 41,000 people and playing a few of his trademark leg glances and pulls.

He scored 53 runs in 65 minutes in the first innings before he was caught out off the bowling of his old teammate, Keith Miller, and did not bat in the second.

Donor had 'no idea' Bradman was in footage

Don Bradman always drew a crowd. ( Supplied: National Film and Sound Archive of Australia )

The 16-millimetre colour footage was shot by George Hobbs, who worked as a cameraman for the Department of Information during World War II and later for ABC TV.

It was donated to the NFSA by George Hobbs's son, Adrian, in a can marked "Manly and Bondi Beach, Sydney, 1949".

The senior curatorial officer at the NFSA, Jeffrey Ray, said the Bradman footage was only discovered when the film was undergoing a technical assessment.

"It was just fascinating that it came in and the donor had no idea that it actually contained Don Bradman footage," Mr Ray said.

"The feeling is quite amazing, because it really is unexpected and to get something that really shows someone of such significance as Sir Donald Bradman in colour and doing what he does best — playing cricket in the middle — is just a very special sort of feeling.

"You can't believe it really, because you've been, I guess, conditioned over life to believe everything was black [and white] over that period of time."

The film was taken the year after Bradman's final Test innings, when he was bowled for a second-ball duck against England at the Oval.

What is not as widely known as that final Test dismissal is that Bradman scored another four centuries in first-class cricket after that Test, including three in England and one during his own testimonial match earlier in Melbourne.

He played one more first-class innings in another testimonial match for AJ Richardson, scoring 30 in the first innings before he sprained his ankle on a sunken water tap while fielding.