Hadush Gerberslasie Kebatu had been staying at The Bell Hotel in the Essex town, with the incident fuelling weeks of protests at the site.
The Ethiopian national was found guilty of two counts of sexual assault, attempted sexual assault, inciting a girl to engage in sexual activity and harassment without violence earlier this month.
District judge Christopher Williams said Kebatu posed a “significant risk of reoffending” when he sentenced him to 12 months in prison in September.
Sky News understands Kebatu was being released from HMP Chelmsford as he was due to be immediately deported.
He was released on the expectation that he would be picked up by immigration enforcement, but it is currently unclear what happened next. It is understood that the Home Office was ready to take Kebatu to an immigration removal centre.
Essex Police launched a manhunt for Kebatu after he was accidentally freed on Friday morning, and the force said in a statement that the asylum seeker boarded a train to London shortly after midday.
“We were informed by the prison service at 12.57pm today of an error this morning surrounding the release of an individual,” Essex police said in a statement.
The force added that “fast-paced enquiries have shown that the man boarded a London-bound train at Chelmsford Railway Station at 12.41pm”.
