Police have not ruled out the possibility that escaped terror suspect Daniel Abed Khalife may have already left the country.
An alert was sent out to all UK airports and ports soon after his breakout on Wednesday morning with security stepped up in an attempt to prevent him fleeing.
But the Metropolitan Police’s counterterrorism commander said he was “keeping an open mind” as to whether he had managed to leave the UK, highlighting the former soldier’s “ingenuity” in making his pre-planned getaway.
He also described 21-year-old Khalife as “very resourceful” and said he may be getting help.
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With more than 150 counterterrorism officers hunting him and border staff on high alert, how could Khalife have made it abroad?
Fugitives, who can’t travel under their own identity, often use forged documents or even genuine passports, which have been fraudulently obtained.
In May, three men were jailed after supplying more than 100 passports to on-the-run criminals including murderers, gun smugglers and drug traffickers.
The gang’s customers, who paid up to £15,000 for a passport, included convicted cannabis supplier Jamie Acourt – one of the original suspects in the racist murder of Stephen Lawrence.
He spent two years on the run in Spain before he was arrested on a European warrant outside a gym in Barcelona in 2018.
Those seeking to evade justice are likely to avoid major transport hubs, instead travelling from smaller ports and airports with less security.
Shane O’Brien fled the country in a private plane from Biggin Hill Airport in southeast London after stabbing 21-year-old Josh Hanson to death in a west London bar in 2015.
After landing in Germany, he used fake documents to travel through Germany, Belgium and the Czech Republic with the help of friends.
He was arrested in Prague in 2017 but managed to slip through the net by using the alias Enzo Melloncelli before he was finally caught in Romania in 2019 and extradited back to the UK to face justice.
For a high-profile escapee such as Khalife, even travelling using fake documents may be too risky.
But he could have been able to get out of the country undetected by boat or hidden in the back of a vehicle.
Mohammed Mokter Hossain, 54, was jailed in June after smuggling hundreds of people in both directions across the Channel using complicit lorry drivers.
They included fugitives who wanted to leave the UK because they were wanted for serious crimes such as child abuse and murder, the National Crime Agency (NCA) said.