Pressure is growing on UK investigators to publish a list of companies alleged to have employed private investigators to engage in such activities as “blagging” information and phone-hacking.

The Serious Organised Crime Agency (SOCA) handed the list of 102 companies – reported to include 10 insurers – to Parliament’s Home Affairs Committee, with the proviso it remain confidential.

But SOCA chairman Sir Ian Andrews has since resigned after failing to disclose an interest in a private consultancy company.

Committee chairman Keith Vaz now says he will push SOCA to review the block on publication.

Critics say while the media has been the focus of police investigations and a high-profile public inquiry, other industries appear to have avoided scrutiny.