He's supposed to give gifts and bring joy around the world, but a man dressed as Santa has stolen a large sum of cash from a Sydney shopping centre.

The Santa impostor broke into a store's office and raided a safe at Westfield shopping centre in Liverpool, south-west Sydney, about 8pm on Sunday, police said.

Bad Santa ... police are searching for a man who stole a large sum of cash. Credit:Police media

Police are appealing for help with their inquiries and have released an image of the man.

"He was pushing a shopping trolley and using a walking stick. In the trolley was a red sack," policesaid.

Wanted man ... a person dressed as Santa stole money from an office in a shopping centre. Credit:Police media

Anyone with information should contact Crime Stoppers on 1800 333 000 or local police.