Counter-terrorism police received more than 800 reports of potential suspicious activity during the security operation after the Queen’s death, double the average level.
Matt Jukes, the head of UK counter-terrorism policing, said one in eight of the reports is being used as intelligence by investigators.
The mammoth policing operation, called Operation London Bridge, also saw 40 drone flights detected across London, with four people now facing prosecution for related offences.
Police and security services reviewed all counter-terrorism investigations in the days after the Queen died to identify any new risks, as well as assessing new information.
Mr Jukes said: “Reviewing current investigations and monitoring new intelligence has been absolutely vital in keeping the public safe over the last 10 days.
“By doing so, we have been able to take steps to ensure developing risk around places or people of interest has been responded to robustly.
“Communities across the country have played a crucial role.
“Every piece of information we receive has the potential to transform an investigation, create opportunity for an arrest or simply helps us build a clearer intelligence picture around someone, or something.
It is difficult to put into words the scale of the policing operation over the last 10 days, it has been nothing short of incredible— Matt Jukes
“After initial assessment, one in eight of the reports we’ve received over the mourning period are now actively being used as intelligence by our investigators.
“You are never wasting our time.”
The UK’s terror threat level is set at “substantial”, meaning an attack is “likely”.
The huge policing and security operation after the death of the Queen saw the biggest ever deployment of armed officers from across the UK, protecting crowds paying their respects as well as the hundreds of foreign dignitaries who attended the funeral.
Mr Jukes added: “It is difficult to put into words the scale of the policing operation over the last 10 days, it has been nothing short of incredible.”
