The SCO Group's letters to Linux users alleging further copyright violations has brought a swift rebuttal from Linux creator Linus Torvalds.

Torvalds (pictured) examined some of the 65 files which SCO's letter claims were copied from Unix, and stated that he wrote some of them himself.

"I can definitely say that those files were trivially written by me personally, with no copying from any Unix code ever," he told the New York Times.

Torvalds admits to being a little ashamed of producing the "horribly ugly" macros as a young C language programmer back in 1991.

SCO claims that its software code was incorporated into Linux without its consent, and is trying to get Linux users to buy licences for its use.

The situation has become further complicated as Novell has issued a statement claiming that it - and not SCO - has always owned the Unix copyrights.

Novell has now obtained copyright registrations from the US Patent and Trademark Office in support of its claim.

The company said in a statement: "Novell believes it owns the copyrights in Unix, and has applied for and received copyright registrations pertaining to Unix consistent with that position."

Novell, the one-time owner of Unix, and now in the process of absorbing open source companies Ximian and SuSE, explained that it has detailed the basis for this ownership position in earlier correspondence with SCO.

"Contrary to SCO's public statements, as demonstrated by this correspondence SCO has been well aware that Novell continues to assert ownership of the Unix copyrights," the company stated.

This correspondence with SCO is published for reference here.