The deputy chairman insists “no individual officer” is under investigation.
The Independent Police Complaints Commission has begun its inquiry into the shooting of three terrorists during the London Bridge attack.
Three terrorists were shot dead and a member of the public sustained a gunshot wound as armed officers put a stop to the murderous rampage which left seven dead and dozens injured on Saturday night.
The Metropolitan Police Service referred the matter, as is protocol, to the IPCC in the early hours of Sunday morning following the incident.
IPCC deputy chairman Sarah Green was keen to stress the body is “conscious” of the ongoing anti-terror operation and promised the IPCC investigation would not get in the way. She said: “We have all been shocked by the terrible events in London on Saturday evening and our thoughts are with everyone who has been affected.
“The IPCC has a duty to investigate fatal police shootings and it is important to stress that we are currently investigating the circumstances of the incident and no individual police officers are under investigation.
"The IPCC and the Metropolitan Police are following agreed working arrangements related to terrorist incidents, which are working well. “We are conscious that the police are conducting a dynamic and ongoing counter terrorism operation and we will ensure that our investigation does not impede that operation.
“The Coroner is being kept informed but it has been agreed that the police investigation takes primacy.
"Our investigators attended the scene at Borough Market and oversaw the post incident procedures early on Sunday morning where the officers involved provided their initial accounts.
“We can confirm that 46 shots in total were fired by eight police officers - three officers from City of London Police and five from the Metropolitan Police.
“We are examining CCTV footage from within Borough Market which we believe shows the majority of the incident relevant to our investigation.
"I recognise that this was a fast-moving and dangerous situation which the police had to respond to extremely quickly. “This investigation is being given the highest priority and we aim to complete it at the earliest opportunity.”