Sydney police search for hotel robber

Police are searching for a robber who stole "a large sum" of cash from a southwestern Sydney hotel.

The man confronted a 21-year-old employee at a hotel in Chester Hill on Saturday morning, told him he had a gun and demanded money.

"He fled with a large sum of cash," police said in a statement.

It's believed the man, who's described as muscular, between 190 and 200 centimetres tall and of Pacific Islander or Maori appearance, was loitering outside for about half an hour before the robbery.

Police said he was last seen wearing black pants, a yellow hi-vis vest and a black hat with "SECURITY" printed on it.