Steve Jobs, chief executive of Apple Computer, was handed 7.5m stock options in 2001 without the required authorisation from the company’s board of directors, according to people familiar with the matter.

Records that purported to show a full board meeting had taken place to approve Mr Jobs’ remuneration, as required by Apple’s procedures, were later falsified. These are now among the pieces of evidence being weighed by the Securities and Exchange Commission as it decides whether to pursue a case against the company or any individuals over the affair, according to these people.

News of the irregularities, which is expected to be revealed in a regulatory filing by Apple before the end of this week, will add to pressure that has been growing on one of Silicon Valley’s most highly-regarded companies since the middle of 2005.

In early trade in New York on Thursday, Apple shares were down 2 per cent to $79.83, but regained lost ground to stand at $80.45, a fall of 1.3 per cent.

Apple is among more than 160 companies that have owned up to stock option backdating – handing options to executives and other employees at exercise prices that were set in hindsight at favourable levels – a scandal which has led to the departure of a number of chief executives.

The latest revelation is likely to add to questions about Apple’s disclosures about its internal investigation into the backdating issue. In October, the company largely exonerated Mr Jobs over the matter, saying that while he had been “aware” of the backdating “in a few instances”, he “did not receive or otherwise benefit from these grants and was unaware of the accounting implications”.

According to an Apple filing in 2002, the options under review were handed to Mr Jobs in October 2001, at an exercise price of $18.30 a share. However, the purported board authorisation was dated near the end of the year, suggesting that the benefits were both not properly authorised and were backdated. Mr Jobs later surrendered his options before they were exercised, implying that he did not gain any direct benefit from them. He was later given a grant of restricted stock by the company instead.

Apple’s lawyers have briefed people involved in the case on the findings of the company’s internal review of the matter, though it remains unclear how much detail will be included in the filing.

Under Apple’s rules, the chief executive’s remuneration must be set by a compensation committee of independent directors and later authorised by the full board.

An Apple spokesman refused to comment on the matter on Wednesday, but said the company had handed the findings of its internal enquiry to the SEC. The company said in October that it had found “no misconduct by any member of Apple’s current management team” but that its investigation “raised serious concerns regarding the actions of two former officers”. At the same time, it also announced the resignation from its board of Fred Andersen, a former chief financial officer. Mr Andersen had not been a director at the time of the 2001 options grant.