British police scoured a park in west London on Friday in their hunt for a former soldier accused of terrorism offences who went on the run from prison earlier this week, with investigators looking into whether his escape was an inside job.
Daniel Abed Khalife, 21, absconded from London's HMP Wandsworth on Wednesday morning after slipping out of the prison kitchen where he was working and strapping himself to the bottom of a food delivery van.
While he is not said to pose a risk to the public, his escape has touched off a massive manhunt across the country, with enhanced security checks at ports and airports which have led to delays for travellers.
So far, there have been no confirmed sightings of Khalife, whose military experience could make him more aware of efforts to catch him, police said.
Some 150 counter-terrorism officers are involved in what London police chief Mark Rowley said was a huge operation to find Khalife. On Friday, police confirmed helicopters were circling London's Richmond Park as part of the search.
Rowley told LBC radio they were investigating whether Khalife, who was wearing a chef's outfit of a white T-shirt, red and white chequered trousers and brown steel toe cap boots, had help from guards or other prisoners in his escape, saying it was "clearly pre-planned".
"So it's a question," Rowley said. "Did anyone inside the prison help him, other prisoners, corrupt guard staff? Was he helped by people outside the walls? Or was it simply all of his own creation?"
Khalife, who was discharged from the British army in May, is accused of eliciting or trying to elicit information likely to be useful to a person preparing an act of terrorism while he was based at barracks in central England in 2021, and also staging a bomb hoax by placing three canisters with wires on a desk.
He is also charged with obtaining information which might be "directly or indirectly useful to an enemy". The BBC has reported he was accused of gathering details for Iran.
Opposition lawmakers have demanded answers about how Khalife had been able to get out of jail and why he was not being held at a maximum-security prison.
Justice minister Alex Chalk told parliament on Thursday there would be an immediate investigation into Wandsworth prison's security protocols and into the decision about where Khalife was held, with preliminary findings due by the end of the week.