A man has been arrested on suspicion of preparing terrorist acts over the suspected terror plot near an RAF base used by the US.

A 27-year-old, a dual UK-Iranian national, was arrested in Westminster, London, on suspicion of preparation of terrorist acts under Section 5 of the Terrorism Act 2006.

A second man, 26, who is a UK national, has also been questioned under caution.

Five men in their mid-20s, who were arrested close to RAF Fairford in Gloucestershire on Sunday on suspicion of explosive offences and terrorism, remain on police bail.

Senior National Coordinator for Counter Terrorism Policing Vicki Evans said: ‘The investigation into circumstances surrounding events in Gloucestershire is hugely complex, and our specialist teams are interrogating multiple lines of enquiry.

‘As we’ve made clear, we’re looking at all possible angles – including possible foreign state involvement. I’d like to thank the public for their continued support and patience whilst we work through this investigation.’

The arrest comes after Prime Minister Andy Burnham claimed there are ‘strong indications that Iran played a part’ in the incident, although he declined to go into further detail. 

But Iran’s London embassy has fiercely denied any involvement in Sunday’s incident. 

Three white vans are investigated by a robot after the alleged plot near RAF Fairford

Mr Burnham told GB News on Wednesday: ‘There are strong indications that Iran played a part in what happened over the weekend. It is, though, still an ongoing and very serious police investigation.’

He added: ‘Obviously, I’ve been dealing with this as I’ve been here in Liverpool [for the Labour Party Conference]. We have held a Cobra meeting here. We are completely on top of things, but will say more when we can.’

Asked about the bail, Mr Burnham told the BBC: ‘I think people need to understand that when it says released – that isn’t as people might think. It’s obviously with the strictest possible bail conditions.

‘The authorities have this under the strongest grip and closest control, and I can assure you of that.’

On Sunday, the farmer who alerted the authorities said one of the three vans in the incident had lettering on the side which appeared to be fake. It carried branding for ‘Fuel 2You’ – unrelated to a real fuel delivery company, Beaconsfield-based ‘Fuel2U’.

It has also been noted that the phone number beneath the company name – 0742 418 2599 – was spaced in a format predominantly used in Iran.

Others pointed out how it was odd to use a red logo for a business supplying fuel, when the colour of petrol pumps in the UK is green. In Iran, the colour is red.

It comes as a video showed the moment a police robot blasted the doors off one of the vans near the base. The clip, exclusively obtained by the Daily Mail, was captured on a resident’s security camera.

Meanwhile, it has been revealed that one of the five men arrested over the plot called police before they were detained.

The suspect phoned around an hour before a farmer said she called 999 at 1.36am on Sunday after discovering three vans blocking a road near the base.

The five British nationals, all in their mid-20s, and from London, were subsequently arrested.

It has also emerged that petrol, but no explosives, was found in the vans which sparked the security alert in the village of Whelford.

This is a breaking news story – more to follow