The review was launched after the FOS was heavily criticised following an undercover investigation by Channel 4’s Dispatches programme, in March, which appeared to show that complaints were being handled by insufficiently trained officials.

The documentary suggested that some officials had to use internet search engines to find out about the products they were considering.

Mr Lloyd, who is vice chair of Money and Mental Health Policy Institute and is UK chairman of complaints handler Resolver, will lead the independent probe and his remit has also been revealed.

He is to be granted “full access and the resources necessary” to carry out a review and can go where the investigation takes him, with unrestricted access to FOS staff and all documents.

The review will be completed by the end of June.

A document published by FOS, in relation to the review’s parameters, read: “The review will assess the evidence presented by Dispatches in respect of each of the issues raised in the programme, to consider whether there are any matters of substance which should be addressed, although it will not be restricted to the issues raised in the programme.

“If the review finds matters for concern, it will seek to identify possible root causes for them (such as management action or inaction, cultural factors, staff objectives and performance management, organisational structure or any other underlying factor) and how they might be addressed.

“The review will also consider staff morale and the factors which contribute to it.”

It was also revealed that the investigation will look into the extent to which the current governance and arrangements for providing assurance about the work of FOS to its board, including whistleblowing procedures, “are applied effectively and consistently.”

As head of the review, Mr Lloyd will be able to make recommendations for strengthening governance and assurance arrangements in his final report.