London: British counter-terrorism police have arrested a 27-year-old dual British-Iranian national as part of an investigation into a security incident near RAF Fairford, a military airbase in Gloucestershire that has been used by the United States for operations involving Iran.

The latest arrest took place in Westminster, London, on October 1. Police said the man was detained on suspicion of preparing terrorist acts under the UK’s Terrorism Act 2006. A second British man, aged 26, was also questioned under caution, while officers searched two properties in London.

The investigation began after five British men in their 20s were arrested near RAF Fairford on September 27 following reports of suspicious vehicles in the area. The five suspects were subsequently released on police bail but remain under investigation.

Police have said investigators are examining several possible explanations for the incident, including the possibility of foreign-state involvement. However, authorities have not publicly established that Iran directed or organised the alleged activity.

The case has nevertheless developed into a diplomatic issue between Britain and Iran. UK Prime Minister Andy Burnham has said there are strong indications that Iran played a role in the incident. Iranian officials have rejected the allegation and denied involvement.

The strategic importance of RAF Fairford has increased the sensitivity surrounding the investigation. The base has been used by American military aircraft, including bombers involved in operations connected to the conflict with Iran. This has made security around the facility a significant concern for British and US authorities.

During the initial investigation, bomb-disposal specialists examined vehicles connected with the suspects. Police reported finding a quantity of petrol but said no viable explosives or improvised explosive device had been discovered.

The arrests have also attracted attention in Washington. US officials have questioned the decision to release the original five suspects on bail, although British counter-terrorism authorities have stressed that the investigation remains active and that the suspects remain subject to restrictions.

British Counter Terrorism Policing has described the investigation as highly complex and said specialist teams are pursuing multiple lines of inquiry. Authorities are examining whether individuals may have acted independently, on behalf of others, or potentially in connection with a foreign state.

For now, the investigation has not produced a final public conclusion about who may have organised the alleged plot or what its precise objective was. The new arrest adds another element to a case that has already raised concerns about Britain’s security environment and its relationship with Iran.

Officials are expected to continue gathering evidence, questioning suspects and examining potential links between the individuals involved. Any decision on charges will depend on the evidence obtained during the ongoing investigation.