A report by Clifford Chance litigation partner Simon Davis has criticised senior figures at the Financial Conduct Authority over their handling of an investigation into long term life assurance products, calling the watchdog's strategy "high-risk, poorly supervised and inadequately controlled".

An independent inquiry, fronted by Davis, was launched in April to look into the FCA's actions during its review of insurance products sold in the UK between the 1970s and 2000. The details of the review were leaked to the Daily Telegraph and major insurers took a hit on their share prices as a result.

Although Davis said the regulator's actions in briefing The Telegraph had been "well intentioned," he criticised the strategy and reaction.

"The strategy and the manner in which it was pursued was, however, high risk, poorly supervised and inadequately controlled," wrote Davies. "When it went wrong, the FCA's reaction was seriously inadequate and fell short of the standards expected of those it regulates."

The City watchdog confirmed that chief executive Martin Wheatley, director of supervision Clive Adamson, director of communications and international Zitah McMillan and director of markets David Lawton would not be receiving bonuses for 2013/14 as a result of Davis' criticism.

The 2013/14 bonus payments for all other members of the FCA executive committee have also been reduced by 25% to reflecting their "collective responsibility."

Clifford Chance charged £2.04m, excluding VAT, for the report, according to the regulator.