A UK-Iranian dual national has been arrested on suspicion of preparation of terrorist acts in connection with the incident at RAF Fairford, counter-terror police have said.
The 27-year-old man was arrested in Westminster, London.
A second man, a 26-year-old UK national, has also been questioned under caution, and two properties in the area have been searched.
Five men in their twenties who were arrested near the airbase on Sunday remain on police bail. All five were UK nationals from London.
Counter-terror police are considering “all possible angles – including foreign state involvement”, the force’s senior national coordinator Vicki Evans said.
“The investigation into circumstances surrounding events in Gloucestershire is hugely complex, and our specialist teams are interrogating multiple lines of enquiry,” she said.
“I’d like to thank the public for their continued support and patience whilst we work through this investigation.”
The five men were arrested in the early hours of Sunday morning after “three suspicious vehicles” were reported travelling towards the base, sparking a major security incident around the Gloucestershire base used by the US Air Force.
The men, aged between 23 and 25, were arrested on suspicion of explosives offences and later on suspicion of preparing a terrorist act. Four live in Westminster and one in Camden, and searches of their homes were carried out.
They were released on bail on Monday in what police described as an “investigative decision” that was “grounded in experience and strategy”.
