British police said on Friday they had charged a 39-year-old man on suspicion of assisting Iran's intelligence service, the latest in a series of incidents involving Tehran and offenses covered under UK National Security laws.
Police said the suspect, Vahid Aberi, from Liverpool, northern England, was taken to a police station in central England and searches had been carried out at addresses in nearby Birmingham and Liverpool.
UK security officials have repeatedly warned that Iran has sought to use criminal proxies to carry out hostile activity in the country. Since the beginning of the US-Iran war, there have been a number of antisemitic attacks in Britain linked to Iran.
Seeking to use new powers designed to stop the use of state-sponsored proxies, Britain banned support for Iran's Islamic Revolutionary Guard Corps earlier this week.
On the Aberi investigation, police said they had not identified any direct threat to any community or individual, but said they were having to intervene more frequently to disrupt suspected activity by foreign intelligence services.
"We have seen a significant and sustained increase in the tempo of our work in national security investigations in recent years," Helen Flanagan, head of counter terrorism policing in London, said in a statement.
Iran rejects claims of being 'a threat to Britain'
Last week, Britain summoned Iran's most senior diplomat over the stabbing of an Iranian journalist in London, for which two Romanians were convicted.
In response to being called a threat to Britain, Iran's embassy in London has previously said it rejected the "unfounded, politically motivated and hostile allegations".
Aberi will appear in court in London later on Friday.