Bonuses handed out to senior bosses at Royal Bank of Scotland are facing renewed scrutiny after the chairman of the bailed-out bank apologised for inaccuracies in evidence given to MPs about its restructuring division.

Sir Philip Hampton admitted evidence given by two of the most senior bankers to the Treasury select committee was incorrect. The division is facing accusations about its treatment of small businesses.

The inaccurate evidence was given in June by Derek Sach, who ran the global restructuring group (GRG) – which is now being shut down – and Chris Sullivan, the deputy chief executive. It is now being re-examined, following an exchange of letters between Hampton and Andrew Tyrie, the MP who chairs the committee.

It has put a fresh focus on the bonuses handed out by the bank. It has previously been reported that £17m of bonuses were handed out in the GRG division. Disclosures have also been made to the Stock Exchange about share awards issued to Sullivan in his capacity as a senior executive at the bank.

In March, prior to the appearance before the committee, Sullivan was awarded shares potentially worth £1.6m under an incentive plan which pays out in three years. He was also handed shares worth £784,900 from schemes relating to previous years. In addition, in August Sullivan – who leaves RBS next year – was handed shares worth £460,000 in “allowances” – payments being used by banks to get round the EU cap on bonuses, which limits bonuses to 100% of salary.

Lawrence Tomlinson – an entrepreneur and an adviser to Vince Cable, and publisher of a report raising issues with the GRG division – said bonuses should be reconsidered: “I cannot comment on the bank’s internal remuneration policy. However, I do know that if one of my employees had brought my company into disrepute by giving misleading answers to a parliamentary committee, I would certainly be looking at a disciplinary procedure and what benefits they’d received for ‘good performance’ that could be returned to the business.”

The row centred on a claim by the RBS executives that GRG was not a “profit centre” and whether GRG was able to transfer customers to other areas of the bank. RBS said that GRG was set up to minimise losses caused by distressed loans and return customers to financial health, although Tomlinson had argued that the division pushed customers to the brink to make a profit from them. Hampton has now admitted the unit was run for profit.

The BBC reported that Sullivan had told Tomlinson to move his business from the bank because trust had irretrievably broken down. The BBC said RBS had said this was because of a long-running dispute over a complaint Tomlinson made in 2012. Two investigations into this complaint had found no evidence of wrongdoing and that Tomlinson had failed to attend a meeting to discuss the findings, the BBC reported that RBS said.

In his letter Hampton said he knew the committee expected highest standards from those who give evidence. “I regret that we have not met these standards on this occasion. Nevertheless, based on the review we have undertaken, it is my view and the view of my colleagues on the board that the bank’s representatives did not intend to mislead the committee.”

Mark Garnier, an MP who sits on the Treasury select committee, said: “If you’ve people who told inexactitudes to the select committee then why not have a crack at their bonuses?”

Garnier also sat on the parliamentary commission on banking standards which has called for bonuses to be deferred over 10 years to make it easier to claw them back should problems be uncovered later.