A reported sighting of on-the-run terror suspect Daniel Khalife “could be very significant”, the Metropolitan Police’s counter-terrorism commander has said.

The force is offering a £20,000 reward for anyone with information that leads to the arrest of the former soldier after he escaped from HMP Wandsworth on Wednesday morning.

Commander Dominic Murphy said the force is investigating after a member of the public saw a man fitting Khalife’s description walking away from a Bidfood van that had stopped near the south entrance to Wandsworth Roundabout shortly after his escape.

Police said the man was then seen walking towards Wandsworth town centre.

Mr Murphy said: “This remains a fast-paced and dynamic investigation, but I want the public to know that a large number of officers are working extremely hard to locate Khalife.

“We have now received more than 100 calls from the public, and we thank everyone who has contacted us with information.

With the reward we are offering today and the amazing support we have had from the public and the media, we will be closing in on you, Daniel, you really need to come in and give yourself up

“The sighting near Wandsworth Roundabout could be very significant, and this is one of many useful lines of inquiry that officers are perusing.”

Mr Murphy urged Khalife to hand himself in to police, warning officers were “closing in” on the terror suspect after he escaped from Wandsworth prison on Wednesday.

He said: “My message to him is to hand yourself in, either call us or go to a local police station and hand yourself in.

“With the reward we are offering today and the amazing support we have had from the public and the media, we will be closing in on you, Daniel, you really need to come in and give yourself up.”

Khalife, an ex-soldier who was awaiting trial after allegedly planting a fake bomb at an RAF base and gathering information that might be useful to terrorists or enemies of the UK, was discharged from the Army in May.

He is believed to have escaped by strapping himself to the bottom of a delivery lorry after leaving the prison kitchen in a cook’s uniform.

The Met released pictures of what the cook’s uniform looks like on Friday – including red and white chequered trousers, a white T-shirt and brown shoes.

Video footage obtained by the PA news agency shows police officers searching a Bidfood lorry with a sniffer dog after it was stopped as witnesses told of their shock as they learned about the incident.

Speaking on LBC on Friday, Met Commissioner Sir Mark Rowley said Khalife’s escape was “clearly pre-planned” and “it is a question” whether it was an inside job.

Sir Mark branded it “extremely concerning” that the 21-year-old, who escaped from HMP Wandsworth in south-west London on Wednesday, was “on the loose”.

The force confirmed officers had been searching overnight in Richmond Park – a few miles from the jail – as the nationwide manhunt entered a third day.

Speaking to broadcasters in New Delhi, Prime Minister Rishi Sunak would not comment on suggestions there could be foreign state involvement in the escape.

Khalife’s disappearance has prompted questions over staffing levels at the Victorian jail and whether he should have been in a higher security prison.

Strapping was found underneath the delivery lorry which police stopped just over an hour after it left the prison at 7.32am, with officers suggesting Khalife held on to the bottom of the vehicle to escape.

Mr Murphy said it is testament to Khalife’s “ingenuity” that there have since been no confirmed sightings of him.

Police have not ruled out the possibility he may have managed to flee the country, despite heightened border checks.

Khalife was declared missing at 7.50am, with police notified at 8.15am. The lorry was stopped on Upper Richmond Road, near the junction of Carlton Drive, at 8.37am.

CCTV footage later emerged of the van driving along a road in London after it had left the prison.

Justice Secretary Alex Chalk confirmed an independent investigation will take place after Khalife’s escape, alongside two urgent reviews looking at the categorisation and placement of all HMP Wandsworth prisoners and all those in custody charged with terrorism offences.

The former soldier, who denied the three charges against him, is described as slim, 6ft 2in, with short brown hair.

Khalife has links to the West Midlands – having been stationed at the Ministry of Defence’s Beacon Barracks in Stafford – and Kingston upon Thames in south-west London, but Mr Murphy said the hunt is covering the whole of the UK.

Police have said there is no reason to believe Khalife poses a threat to the public but urged people not to approach him if they spot him and to call 999.