A partner from the law firm representing a film industry trade group in its battle against ISP iiNet has sent an email telling staff "not to ever use" BitTorrent on its corporate internet account.

Gilbert and Tobin partner Peter Leonard told iTnews that he "sent an email around the use of sites like BitTorrent" and told staff they were "not to ever use them".

The firm represented the Australian Federation Against Copyright Theft (AFACT), which alleged in the Federal Court last year that iiNet authorised illicit copying of films, a case the WA ISP won in February.

News of the BitTorrent ban surfaced after legal news and gossip site Firmspy reported the contents of the email purportedly sent by Leonard to the rest of the law firm on October 19.

Leonard would not confirm that the email posted to Firmspy was the same as the one he told iTnews he sent to staff.

The blog said an employee of the firm was caught using BitTorrent on the corporate internet account.

"We recently had an instance of a person downloading from BitTorrent on the G+T account," read the email published to Firmspy.

"This is clearly contrary to G+T's Communications Policy. Even more importantly, it is illegal and (therefore) just plain stupid.

"There should be non peer to peer download activity using G+T resources."

The allegation - if proven - could be damaging because the film industry has repeatedly claimed that most uses of BitTorrent were illegal, despite evidence of legitimate uses for the peer-to-peer protocol.

Liz Tay contributed to this report.