Hadush Gerberslasie Kebatu, 38, was sentenced to a 12-month term in September for sexually assaulting a 14-year-old girl and a woman.

His arrest in July led to protests outside the Bell Hotel in Epping, 20 miles (32 km) north of London, which became a touch-paper for other demonstrations amid rising tensions over immigration.

Britain’s Secretary of State for Justice David Lammy said he was “appalled” by the error at Chelmsford prison.

Kebatu was meant to be sent to an immigration detention centre to be deported, but was freed by mistake.

“We are urgently working with the police to track him down, and I’ve ordered an urgent investigation,” Lammy said on X.

“Kebatu must be deported for his crimes, not on our streets.”