Updated Half of the charges made against the four men behind the notorious file-sharing website The Pirate Bay have been sensationally dropped on day two of the trial.

Prosecutor Håkan Roswall made the surprise move this morning, according to reports on The Local and TorrentFreak.

He has amended the charges against Carl Lundström, Peter Sunde, Frederik Neij and Gottfrid Svartholm Warg by removing all mention of "complicity in the production of copyrighted material" from the charge sheet filed with the district court in Stockholm, Sweden.

The new charges will be changed simply to read “complicity to make (copyrighted material) available”, thereby limiting it to the production of the actual torrent file and the resultant hard or soft copy of it.

Defence lawyer Per Samuelsson described the amendment as “a sensation".

"It is very rare that you win half the case after one and a half days and it is clear that the prosecutor has been deeply affected by what we said yesterday," he said.

Samuelsson also claimed that Roswall “has not really understood” the BitTorrent technology used by The Pirate Bay.

The prosecutor reportedly used media evidence that included Harry Potter , Syriana and Walk the Line downloads in court yesterday. According to TorrentFreak, Roswall was forced to amend the charges today after failing to prove that the torrent files had used The Pirate Bay's tracker.

The Register asked the Stockholm district court if it can confirm Roswall’s amendment to the charge sheet, but at time of writing it hadn’t responded to our request. ®

Update

The International Federation of the Phonographic Industry has issued a statement in which it downplayed the significance of Roswall's amendments to the charges against the four men in the Pirate Bay case.

It confirmed that the prosecutor had removed the charges relating to "copying, as opposed to making available, copyrighted works."

The IFPI's legal counsel Peter Danowsky said: “It’s a largely technical issue that changes nothing in terms of our compensation claims and has no bearing whatsoever on the main case against The Pirate Bay.

"In fact it simplifies the prosecutor’s case by allowing him to focus on the main issue, which is the making available of copyrighted works."