The head of a national police unit has refused to publish a list of clients of rogue private detectives despite an ultimatum from MPs.

The move paves the way for the Home Affairs Select Committee to release the names on the controversial list after it threatened to do so earlier this week.

Trevor Pearce, director general of the Serious Organised Crime Agency (Soca), has written to the committee chairman Keith Vaz MP to reject his call for the list - featuring law firms, insurance companies, financial services groups and celebrities - to be published by Monday.

The names of 102 firms and individuals who allegedly used corrupt private investigators was handed from Soca to the committee earlier this year on condition it was not published - sparking a row over transparency.