Police have revealed they may have found the source of the deadly nerve agent Novichok which left one person dead and another seriously ill.
Mother-of-three Dawn Sturgess, 44, and her partner Charles Rowley, 45, were exposed to the substance last month. Ms Sturgess died, while Mr Rowley remains seriously ill in hospital.
On Friday, New Scotland Yard revealed that searches of Mr Rowley’s home in Amesbury had turned up a small bottle - and that lab tests confirmed it contained Novichok.
So what do we know about it?
The deadly nerve agent was discovered in a bottle found during searches of Charles Rowley's house in Amesbury.
It was then taken to the Defence, Science and Technology Laboratory (DSTL) at Porton Down for tests where scientists confirmed it as Novichok.
No. The bottle was discovered on July 11th - almost two weeks after Charles Rowley and Dawn Sturgess fell ill.
Jerry Smith, a former chemical weapons inspector, says it is hugely significant - but urged caution.
"This discovery today is hugely significant on a number of levels. Firstly in regards to the investigation, the possibility of a piece of evidence that was actually used in the attempted assignation may mean that there is evidence for the police investigation to follow up such as DNA or finger prints."
He added: "We need to consider that there may be other sources and other containers out there, we can't just rely on this being the only one."
Scientists at Porton Down are carrying out more tests to see if the Novichok is from the same 'batch' that contaminated Sergei and Yulia Skripal in March.
It's believed to be days or weeks before we know the answer - if the information is ever released