Music Industry Piracy Investigations (MIPI) has raided Perth ISP Swiftel, claiming the company used the BitTorrent peer-to-peer technology to link to sound and video recordings.

Music industry investigators and lawyers entered the Swiftel premises Thursday afternoon under Anton Piller orders issued the previous day by the Federal Magistrates Court in Sydney.

MIPI general manager, Michael Speck, said he and his team were gathering evidence of copyright infringement.

"We have identified Swiftel as an ISP which has adopted BitTorrent technology to link infringers to music clips and sound recordings," Speck said.

"We believe hundreds of thousands of downloads have been conducted during the last year in breach of copyright laws."

He said Swiftel used BitTorrent to conduct "high volume sophisticated linking" for its customer base: "They've been operated from within."

However, Ryan O'Hare, CEO of Swiftel parent company People Telecom, said the matter concerned Swiftel customers, not the ISP. "We haven't adopted anything like that [BitTorrent]. We deny that," he said.

"There's no evidence that we have any activity in this way.

"It's about one or a few Swiftel customers."

But Speck said the evidence was located at Swiftel, not elsewhere.

"Look, there's no doubt this is about the ISP," he said.

MIPI has previously said its strategy is not to target individual users, rather larger organised infringement.

Speck said MIPI would take its evidence back to the Federal Magistrates Court next week.