UK police on Sunday arrested an Ethiopian asylum seeker and convicted sex offender, whose crimes had sparked anti-immigration protests, after he was accidentally released from prison in an embarrassing blunder by officials.

“We have ordered an investigation to establish what went wrong. We must make sure this doesn’t happen again,” he wrote on social media.

Kebatu, 38, had served the first month of a one-year sentence for sexually assaulting a teenage girl and a woman, and was reportedly scheduled to be deported when the Prison Service error happened on Friday.

His high-profile case earlier this year in Epping, northeast of London, sparked demonstrations in various English towns and cities where asylum seekers were believed to be housed, as well as counter-protests.

The Metropolitan Police said it received a tip-off Kebatu was at a bus stop in London’s Finsbury Park neighbourhood and officers found him inside that park. He was arrested for “being unlawfully at large”.