Daniel Abed Khalife, a serving British Army soldier, is thought to have used straps to cling on to a food delivery van while wearing a chef’s uniform.
He was reported to the Metropolitan Police this morning after he was reported missing from HMP Wandsworth, where he was being held.
It is believed that he escaped from the Category B prison at 7.50am.
The 21-year-old is being held in prison while awaiting trial for terror charges and Official Secrets Act offences. This includes placing cannisters with wires on a desk at an RAF base in an apparent bomb hoax.
An alert has been sent to all UK ports and airports amid reports of long queues at border control.
Khalife has connections to Kingston and police believe he is “most likely” in London, although he may have travelled further afield.