Vandals used explosives to blow up the famous 25-metre statue of a golden pheasant outside Gumbuya Park east of Melbourne yesterday, police say.

The explosion caused about $50,000 damage to the large concrete bird, made famous in television advertisements for the theme park in Tynong in the 1980s and 90s.

The giant pheasant at the entrance to Gumbuya Park.

A Victoria Police spokeswoman said the vandals were believed to have broken into the Princes Highway venue about 2am yesterday.

"Once inside, it's believed the bandits used some sort of explosive device to blow up the 25 metre statue, causing extensive damage to its rear end," the spokeswoman said.