Suspected terrorist soldier Daniel Khalife escaped from Wandsworth prison on Wednesday.
So far there have been no confirmed sightings despite a nationwide manhunt, police said.
Here are some of the questions about the incident which remain unanswered:
– Why was Khalife in Wandsworth and not a higher security prison?
Khalife was reportedly initially in custody at maximum security Belmarsh prison, where terrorist prisoners and those accused of such offences are often held, but later transferred to Wandsworth.
John Podmore, a former governor at HMP Brixton and HMP Belmarsh, told the BBC Radio 4’s World At One: “My view is that he should have been at Belmarsh.
“It’s much more suited to the levels of security that someone like this – charged with, not convicted – needs. I can’t understand why he wasn’t at Belmarsh.”
– Why was he allowed to work in the kitchen?
Chief inspector of prisons Charlie Taylor told the PA news agency a prisoner has to earn a “certain level of trust” in order to be allowed to work in a kitchen.
He said: “If you’re a prisoner who’s working in the kitchen, you would have earned a certain level of trust anyway, because you would have been seen as someone who could be safe around things like knives, so you would only be allowed to do that and you earn some trust as a prisoner, so you would have kept your nose clean.”
– Was this a pre-planned escape, an inside job, and did he get any other help?
Police have not divulged their theories on this or whether there is any evidence to suggest this, but it will form part of their investigation.
No-one has been arrested or interviewed under caution in connection with the incident.
Mr Podmore also told the BBC programme there was a “possibility” Khalife’s escape was an inside job.
– Are staffing shortages a factor in how the escape was able to take place?
Mr Taylor said inspectors are “particularly concerned” about staffing at the prison, adding: “That ultimately is the source of many of the problems in the jail.”
Wandsworth has one of the highest rates of sickness absence among staff, official Government figures show.
Unions and watchdogs say they have raised repeated concerns about staffing levels there.
– When will a royal commission looking at the criminal justice system be launched, as promised in the Conservative manifesto?
Ministers are facing growing calls to urgently honour its manifesto pledge of carrying out a review of the criminal justice system.
Prison officers’ union the POA called for an “urgent” royal commission in the wake of the incident, saying that, without one, problems are “just going to get worse”.
So far the Government has been unable to say what recent progress has been made to honour the commitment.