A McDonald's drive through in Sydney suffered its second robbery within a span of one week.

Police said the second hold-up incident of the fast food chain's outlet on the corner of Merrylands and Woodville Road took place before Sunday midnight. A masked man, who brandished a shortened double-barrel shotgun held up the store's cashier, got an undisclosed amount and ran way onto Merrylands Road.

The hold-up suspect was about 170 centimeters tall, is thin and wore a black mask, hoodie and pants.

The same store was held up on Wednesday before 1 a.m. The police are investigating if there is a link between the two robbery incidents because of similarities between the styles of the two thieves, who both ran onto Merrylands Road after the getting cash.

The police are also looking into the link between the two McDonald's robberies and the loss of several rifles and shotgun from the Edward Streets house.

To help solve the crimes, the police are reviewing McDonald's CCTV footage.