Novichok in perfume bottle could have caused 'mass fatalities'

Deputy Assistant Commissioner Dean Haydon blasted Russia's military intelligence service for the "reckless" attack launched on Sergei Skripal in March.

He told the BBC the initial stages of the investigation were like looking for "a needle in a haystack", adding: "Actually at that stage we didn’t even have a haystack, so we had to build the data from literally the start.”

But as evidence mounted, investigators discovered that the Salisbury assassins travelled to the UK on false passports.

They were later identified as officers with Russia’s military intelligence service, the GRU.

DAC Haydon told BBC's Panorama: “We had seized over 11,000 hours of CCTV, that was a massive task.

"We were sifting through the CCTV and we had a kind of gotcha moment of we identified the attackers. We were now onto them…I don’t think they expected to be captured on CCTV in the way that they were.”

And he said the amount of Novichok in the bottle could have resulted in mass casualties.

He said: “When we found it there was a significant amount of Novichok contained within the bottle.”

When asked how many people it could have killed he added: “It’s difficult to say, you know, possibly into the thousands….

"The amount that was in the bottle, and the way it was applied to the Skripals' home address, was completely reckless.”

The investigation into the Salisbury attack continues.

READ: Detective tells of 'petrifying' moment he knew he'd been poisoned with deadly Novichok>>>

DAC Haydon said: “Who else is involved is still very much subject to a live line of inquiry.

"My ambition remains to bring these two individuals and anyone else involved in this attack plot to justice, you know through the British criminal justice system. I will not give up.”

Panorama: Salisbury Nerve Agent Attack - The Inside Story, will be broadcast on BBC One tonight (Thursday) at 8pm.