The surprise re-emergence of Melbourne Demon’s 1948 premiership flag on an internet auction site has alerted the Melbourne Football Club that it is also missing five other premiership flags.

The Demons are now aware that the 1926, 1941, 1955, 1956 and 1957 flags are no longer in the club collection.

The person who came to posses the 1948 item has advertised it for $80,000on eBay.

Melbourne received a tip-off and reported the matter to the AFL. Police tracked the flag to a house in Moama, north of the Murray River, in New South Wales.

The flag - one of 12 the club has won since 1900 - is in a fragile state. Its discovery raises the question of how it ended up out of the Demons' possession in the first place.