Police have secured a warrant to further detain three men arrested last week on suspicion of spying for Iran, allegedly targeting individuals and locations linked to the Jewish community.
The suspects, apprehended under the National Security Act, can now be held in custody until 20 March.
Four men, aged 22, 40, 52, and 55, were initially arrested in the early hours of 6 March at addresses across Harrow, Watford, and Barnet.
Detectives from Counter Terrorism Policing (CTP) London had previously obtained warrants allowing their detention until 13 March, before the latest extension was granted.
Deputy Assistant Commissioner Vicki Evans, senior national co-ordinator for CTP, said: “This investigation continues at pace with a number of lines of inquiry being pursued by our detectives.
“The warrants of further detention for these three men will allow us to continue the investigation, while mitigating any potential risk to the public as we do so.
“This has been a long-running investigation and part of our ongoing work to disrupt malign activity where we suspect it.
“We fully recognise that the public – and in particular the Jewish community – may be concerned but I also hope the action we have taken reassures them that we will not hesitate to take action if we think there may be a threat to their safety.
“As ever, I would ask them to remain vigilant and if they see or hear anything that concerns them, then to contact us.”
The Metropolitan Police said: “The investigation, which is being led by detectives from CTP London, relates to suspected surveillance of locations and individuals linked to the Jewish community in the London area.”
The force added: “As part of the investigation 11 searches have been carried out across the London and Watford areas.
“A number of items have been seized, including various digital devices, which are in the process of being examined by specialist officers.”
The 55-year-old has since been released from police custody without charge.
Six other men aged between 20 and 49 were arrested at the same location in Harrow on suspicion of assisting an offender, with one further arrested on suspicion of assaulting a police officer.
All six have been released on bail to dates in May and June pending further inquiries.
