Despite Apple's claims that Steve Jobs was not aware of the backdating of stock-option grants, federal authorities in the US are actively investigating the matter, according to a report in the Wall Street Journal.

Jobs received 7.5 million stock options finalised in December 2001, when Apple's share price was higher than the dates were granted. Apple claims that its board approved grants dated in October 2001 on August 29, when the stock traded at $17.83, but the grant wasn't authorised by the board until 18 December 2001, when the stock traded at $21.01.

The grant was backdated to 19 October, and the share price was $18.30.

Apple says that Jobs didn't understand the the “accounting implications” of backdated grants, and didn't benefit anyway because he didn't exercise the options.

The falsified documents are believed to have been made by an attorney, who, in turn, claims she was acting under the instruction of Nancy Heinen, Apple's then general counsel.