Victims of the Equitable Life scandal expressed dismay yesterday as another professional investigation petered out.

The Financial Reporting Council (FRC) has closed a three-year investigation into actuaries in the Government Actuaries Department (GAD) and one actuary in Ernst & Young, and will take no further action.

The Accountancy and Actuarial Discipline Board, an operating board of the FRC, said in both cases there was "no realistic prospect that a Tribunal would make an adverse finding" against any actuary.

Paul Weir, spokesman for the 40,000-strong Equitable Members' Action Group, said: "If there is no prospect of successful disciplinary action, why has it taken almost three years to reach that conclusion?

"Victims will be bitterly disappointed that once again nobody in the GAD is being held to account, despite the Parliamentary Ombudsman's finding there had been a decade of failure."

A spokesperson for Ernst & Young said it did not intend to identify the actuary concerned.

Equitable was brought to its knees in 2000 after failing to make proper provision in its accounts for the expensive pension promises made to policyholders.

In 2004 the Equitable board launched legal action against Ernst & Young and 15 former directors for £3.3 billion, but were forced to abandon the director cases and then the £2bn claim against the society's former auditors by the end of 2005.

On the conclusion in 2009 of a five-year investigation by the accountancy profession's Joint Disciplinary Scheme into the audit of Equitable Life, Ernst & Young went to the High Court to prevent details of being published.

Mr Weir said the compensation scheme launched last year had not hit its promised target.