About 20 unmarked police officers arrived at the building in Holborn, central London, on Wednesday and left with “files, documents and a computer”. The Telegraph understands that the raid is linked to union members’ money to build a hotel and a convention center in Birmingham. Sharon Graham, the new secretary general, announced last December that she had commissioned a QC-led inquiry after it emerged that the value of the building was significantly lower than its construction cost. He was elected after Len McCluskey, who led the union for 11 years, retired.

Checking contracts

Unite came under scrutiny last year for its decision to award contracts to the Flanagan Group, led by Mr McCluskey’s longtime friend Paul Flanagan, as well as a health and safety contract awarded to SSC, a company owned by David Anderson, the son. of Joe Anderson, the former mayor of Liverpool. South Wales police, who are leading the investigation into bribery and fraud allegations with HM Revenue and Customs, say warrants have been issued across the country. The force added that “a number of suspects will be interrogated.” A spokesman said: “South Wales police have carried out warrants in connection with allegations of bribery, fraud and money laundering. The warrants were issued Wednesday, April 6, at addresses in South Wales, Metropolitan, Merseyside, Cheshire, North Wales, Dyfed-Powys and Northamptonshire. “The joint investigation with the Ministry of Revenue and Customs of His Majesty continues and several suspects will be investigated in due course.” Unite is the second largest trade union in the United Kingdom, with more than 1.2 million members in various sectors, including construction, logistics, manufacturing and transport. A spokesman for the group said: “A Unite employee is currently under criminal investigation by the police. The employee’s office at Unite HQ, in Holborn, London, was accessed and searched by the police on a warrant.