An investigation has opened after a Bow man died in police custody shortly after being detained by officers in an East End pub.

Michael Sweeney, 38, was pronounced dead at the Royal London hospital after being taken there in a police van following the run-in at the Approach Tavern in Bethnal Green on Monday evening.

Police say they were responding to reports that there was a man in the pub with a knife.

The Independent Police Complaints Commission – the watchdog for the Met – has now ordered a probe into the death.

IPCC commissioner Sarah Green said: “This investigation will examine the initial police response, the decision-making behind when and how to take him to hospital and the care he received while being transported, as well as any interaction between police officers and the man when at the hospital.”

When police arrived at the pub at around 7.40pm they decided to call an ambulance to take Mr Sweeney to hospital rather than to a police station but no ambulance units were available.

Mr Sweeney was treated at hospital but was pronounced dead at 10.07pm.

IPCC officers were deployed to the pub that night and have been examining CCTV footage, police records and radio traffic and have also been speaking to witnesses.

Friends of Mr Sweeney told the Guardian newspaper he was about to become a father for the first time.

A spokesman for the Metropolitan police said: “At 7.25pm police were called to the Approach Tavern following reports of a male in a possession of a knife.

“Officers attended and detained the male who was taken to Royal London Hospital by police where the male subsequently died. The matter has been handed to the IPCC.”