Kazaa has three to four million users at any one time

Lawyers for Sharman Networks applied to dismiss the evidence after Sydney Federal Court allowed 12 raids in three Australian states on Friday.

Record company investigators had been seeking instances of music "piracy".

They want Kazaa closed down for alleged copyright infringement. Kazaa has condemned the raids as "unnecessary".

The raids against universities and internet companies were conducted by Music Industry Piracy Investigations (MIPI), which is funded by six major Australian record labels.

Move condemned

Targeting 12 sites in three states, it was operating under a rarely-used law that allows civil litigants to gather evidence from parties they are suing.

The homes of Sharman's chief executive and technology director were among the addresses searched.

Condemning the move, Kazaa owner Sharman said it had already provided similar evidence for US legal proceedings.

In a statement it accused plaintiffs of "using the legal equivalent of a nuclear bomb" to obtain documents already produced in America.

Sharman applied for the case to be delayed until after a ruling on the US case. A judge at the Australian Federal Court adjourned it until 20 February.

Kazaa's Media Desktop software, which allows users to swap music, movies and other computer files, has up to four million users at any one time.