A report commissioned by CommInsure into claims of unethical behaviour at the Commonwealth Bank's insurance arm has cleared the life insurer of "systemic" and "cultural" problems, despite not speaking to any of the victims nor Benjamin Koh, the whistleblower who revealed the scandal.

The review from accountancy firm Deloitte comes after an investigation by the ABC's Four Corners and Fairfax Media revealed cases where claims were delayed or denied to terminally ill people.

The Deloitte report is one of three commissioned by the CommInsure Board, alongside reviews last year from DLA Piper and Ernst & Young, which are yet to be released.

In a statement released late yesterday, the Commonwealth Bank said the report "did not identify issues relating to historically denied claims".

Deloitte also found that there was no evidence to find that improvements ordered in the wake of the scandal would result in delivering "poor customer outcomes".

"The work performed is sufficient to have reasonably identified any matters that may systemically affect the declined claims population," it said.

CommInsure managing director Helen Troupe was not available to speak with the ABC despite requests, but said in a media release the report "identified some instances" where customers were treated poorly.

The CBA's group executive of wealth management, Annabel Spring, said the bank had taken a "robust, independent and wide-ranging approach" to investigating the allegations.

The review was undertaken over 10 months, involved at least 150 people and reviewed more than five million emails relating to the treatment of claims.

Deloitte should have spoken to the claimants: Senator

However, the Deloitte review has already been criticised by Nationals senator John Williams for not talking directly to complainants.

Loading...

"Deloitte should have spoken to the claimants and heard their side of the story, what they've suffered over many years for not being paid their legitimate claims," Senator Williams told AM.

Senator Williams, a member of a joint parliamentary committee examining the life insurance industry, also questioned why the whistleblower, Dr Koh, was not interviewed by Deloitte.

"They should have spoken to Dr Koh who I think is a courageous man for what he has done and what he has said," Senator Williams said.

"There are always two sides to an argument and I think Deloitte has not had a look at the other side."

Commonwealth Bank chief executive Ian Narev, who trumpeted the coming Deloitte review a fortnight ago, will be questioned on CommInsure when he faces the House Economics committee on Friday.

All three reviews have been provided to the Australian Securities & Investments Commission (ASIC) and the Australian Prudential Regulation Authority.