The SCO Group has slammed as "inaccurate" suggestions an e-mail from one of its own engineers showed Linux did not contain copyright Unix code.

The 2002 e-mail, published by Internet law site Groklaw as part of its ongoing coverage of SCO's copyright infringement claims against Linux vendor IBM and user Autozone, was sent to a senior vice president at the company by an in-house engineer and later forwarded on to chief executive Darl McBride.

"At the end, we had found absolutely nothing ie (sic) no evidence of any copyright infringement whatsoever," engineer Michael Davidson wrote of his and an external consultants' attempts to find copyrighted Unix code in Linux.

However, SCO said in a statement this afternoon, "it would simply be inaccurate - and misleading -- to use Mr Davidson's e-mail to suggest that SCO's internal investigation revealed no problems."

SCO e-mailed the media a memo sent in 1999 from that external consultant, Robert Swartz, to SCO's Steve Sabbath, who was at the time the company's general counsel. The memo details Swartz's initial findings which -- according to the vendor -- demonstrate there is cause for concern as to whether portions of protected Unix code were copied into Linux.

"This memo shows that Mr. Davidson's e-mail is referring to an investigation limited to literal copying, which is not the standard for copyright violations, and which can be avoided by deliberate obfuscation, as the memo itself points out," the company continued. SCO also pointed out its legal wrangling with IBM dealt with more recent versions of the Linux code than were mentioned in the memo.

"Even more importantly, this memo shows that there are problems with Linux. It also notes that additional investigation is required to locate all of the problems, which SCO has been continuing in discovery in the IBM and Autozone cases," said SCO.

SCO sued IBM in 2003 for more than US$1 billion, alleging that IBM had misappropriated Unix technology to which SCO claimed intellectual property rights.