British police arrested a fourth Iranian man on Friday in connection with alleged plot against national security that was being hatched in north-west London.
The unnamed man was arrested in the same part of London as three others who were detained in raids by counter-terrorism police last weekend.
A statement said the 31-year-old man was arrested under section 27 of the National Security Act 2023. It connected the suspect to three others, aged 39, 44 and 55 a week ago.
Intelligence experts have briefed that the UK police appear to have disrupted separate operations by different parts of Iran's security forces.
The London investigation is not connected to the arrest of five people last weekend in other parts of the UK.
That group was arrested on suspicion of preparing an act of terrorism and allegedly belong to Unit 840, which carries out assassination and kidnapping missions for Tehran's Islamic Revolutionary Guards Corps.
Two men aged 29 were detained in Swindon in Wiltshire and Stockport in Cheshire, a 40-year-old was held in Rochdale, Greater Manchester, a 46-year-old in west London and a 24-year-old was detained in the city of Manchester.
Reports have identified the Israeli embassy in Knightsbridge as the target of the alleged plotters and officials have claimed the attack was imminent.
UK special forces and counter-terrorism police carried out the raids after what appears to have been an extensive surveillance operation by MI5, the UK secret security service.
The London arrests are said to have separately involved the round up of men from Iran’s Ministry of Intelligence, also known as Vevak, who are more conventionally trained than Unit 840. No target for that plot has been revealed.
Abbas Araghchi, Iran’s Foreign Minister, said this week his country “categorically rejects any involvement” in any alleged plot to conduct attacks in Britain. Iran also called on Britain to provide consular access to the detained Iranians.
UK minsters have since revealed that senior government adviser Jonathan Hall had been asked by Home Secretary Yvette Cooper to review how new legal counter terrorism measures “could be applied to modern day state threats, such as those from Iran”.
That report is now ready and expected to be revealed in the next few weeks.
