Australian rock band Men at Work are fighting accusations that the melody of their 1980s international hit, "Down Under," was stolen from a popular children's song about a bird.

Publisher Larrikin Music is suing for compensation from royalties earned by Men at Work.

On Friday, lawyers for the band's recording companies -- Sony BMG Music Entertainment and EMI Songs Australia -- asked for the case to be dismissed. They reject Larrikin's claim that the distinctive flute riff in "Down Under" was copied from the refrain of a 1934 children's tune, "Kookaburra Sits in the Old Gum Tree."

They also question whether Larrikin even holds the copyright to that song -- a Girl Guide campfire favorite from New Zealand to Canada -- and therefore whether it has the right to sue.

The song about the kookaburra, a kingfisher native to Australia, was written by a teacher named Marion Sinclair for a Girl Guides competition. Sinclair died in 1988.

"My best submission is that Girl Guides have (the copyright)," said lawyer David Catterns, who represents Sony and EMI.

But Larrikin claims that it bought the copyright to "Kookaburra" after Sinclair's death.

Lawyer David Yates told the court this week that "Down Under" reproduced a "substantial part" of the Girl Guide song without permission or payment of royalties to Larrikin and Sinclair.

New South Wales Federal Court Judge Peter Jacobson is expected to hand down a decision on the copyright within a week.

If he decides Larrikin holds the "Kookaburra" copyright, that clears the way for a further hearing about whether the song's refrain was copied in the Men At Work song.

"Down Under" and the album it was on, "Business As Usual," reached No. 1 on the Australian, American and British charts in early 1983. The song remains an unofficial anthem for Australia and was ranked fourth in a 2001 music industry survey of the best Australian songs. Men at Work won the 1983 Grammy Award for Best New Artist.