An employee from the Unite union is being investigated by police as part of an inquiry into allegations of bribery, fraud and money laundering.
The trade union confirmed that officers searched an unnamed employee's office at its Holborn headquarters under warrant on Wednesday.
This case it will, of course, all have a innocent explanation. No Union member especially of a union so closely connected to the Labour Party could possibly behave in such a terrible way. The people involved must all be closet members of the Conservative Party.
Police said that "a number of suspects will be interviewed in due course", and that addresses were in the South Wales, Metropolitan, Merseyside, Cheshire, North Wales, Dyfed Powys and Northamptonshire police force areas.