Man found with gun near Rosehill Gardens

A loaded shot gun has allegedly been found in the backpack of a man stopped among crowds near horse racing's iconic Golden Slipper Day in Sydney.

Police say the man tried to run away after being stopped by officers conducting foot patrols near the intersection of James Ruse Drive and Hassall St at Rosehill about 5.15pm on Saturday.

He did not enter the Rosehill Gardens Racecourse, and the Australian Turf Club said in a statement that there was nothing to suggest he was targeting the race or racegoers.

A loaded sawn-off shotgun, a mask, gloves and ammunition were found in his backpack when he was stopped a street away from the racecourse, police say.

The 39-year-old has been charged with a string of offences, including being armed with intent and possess a loaded firearm.

He is due to appear in Parramatta bail court on Sunday.