Ethiopian national Hadush Gerberslasie Kebatu, 38, who had been living at the Bell Hotel in Epping, was jailed for 12 months in September.
The Sun first reported on Friday that he was meant to be sent to an immigration detention centre to be deported but was freed by mistake.
A police investigation is now under way to find Kebatu.
Deputy Prime Minister David Lammy is said to be furious and has ordered an investigation and is supporting police efforts, according to a Government source.
Sentencing Kebatu last month, a judge told him his behaviour “really highlights the poor regard you must have for women”.
The 38-year-old, who arrived in the UK on a small boat days before the incidents, told two teenagers he wanted to “have a baby with each of them” and attempted to kiss them, before going on to put his hand on one of the girls’ thighs and stroke her hair, his trial was told.
His case led to protesters and counter-protesters taking to the streets in Epping, Essex, and eventually outside hotels housing asylum seekers across the country.
