Hundreds of complaints from dissatisfied consumers has caused the "McMatch and Win" promotion by fast food chain McDonald's Australia Ltd to come under Australian Competition and Consumer Commission scrutiny.

"The ACCC has received complaints from consumers who believe that they had won prizes but were told by McDonald's their claims were invalid," Acting ACCC Chairman, Mr Allan Asher, said today.

"These claims have come from all over Australia, so the ACCC today has written to McDonald's seeking an explanation.

"Under the promotion, consumers buy particular items from McDonald's outlets and receive a game stamp. To play, consumers must peel the label off the container to reveal the game stamps. The game stamps, named after various Monopoly locations, must be matched to the corresponding property printed on the front of a special McDonald's tray mat. If a consumer collects all properties of the same set they win a prize.

"Complaints have been received from consumers who believed that they had correctly matched the properties from recently purchased McDonald's products but have had claims for prizes rejected. The ACCC wishes to ensure legitimate claims by consumers are honoured".

Mr Asher said the ACCC expected the company to respond quickly to the ACCC's inquiries.