By James Lynn
BBC News, Newcastle
The amount of ricin Ian Davison produced could have killed thousands
The discovery of ricin at the home of Ian Davison convinced detectives that the white supremacist was a "serious terrorist".
Found in a jam jar, the cloudy liquid had been extracted from castor beans.
An amount roughly equivalent to a grain of salt is enough to kill an adult, making it 1,000 times more poisonous than cyanide.
Experts admit the toxin is relatively easy to produce, but police are unsure exactly how Davison intended to use it.
The ricin discovered at his house in Burnopfield, County Durham, could theoretically have been used to kill thousands.
However, the poison is most deadly when inhaled or injected directly into the bloodstream, so the quantity found at Myrtle Grove would seem unsuitable for a terrorist planning to unleash widespread mayhem.
If added to food, for example, it is far less dangerous because the toxins are broken down by the stomach.
Ricin was notoriously used in London during the Cold War to assassinate the Bulgarian dissident Georgi Markov.
A specially-equipped umbrella was used to inject a pellet coated with 450 micrograms of ricin into his calf. He died several days later.
The poison works by disrupting the machinery that the body's cells use to renew themselves.
Dr John Gatehouse from Durham University's School of Biological and Biomedical Sciences said: "What the ricin does is it stops that machinery working and it doesn't just stop it in an inert way, it's actually an active toxin.
"So a single molecule of ricin will shut down the entire cellular machinery from renewing itself and when that happens the cell dies."
He added: "It's really difficult to deal with because it starts to kill cells anywhere the bloodstream can reach and it's very effective because such a small amount of it is enough to kill a cell."
An antidote has been developed, but Dr Gatehouse said: "If you can block it from binding to cells you can stop it but you have to get that antidote in pretty quick. Once it's started to work then you're done for basically".
Davison, the founder of neo-Nazi group the Aryan Strike Force, has been jailed for terrorism offences, along with his 19-year-old son Nicky, who was also a leading member of the group.
The 41-year-old was initially arrested when another force made Durham Police aware of the online activities of the ASF.
Only afterwards did detectives discover the ricin, along with terror manuals and pipe bombs.
The Davisons have both been jailed for plotting terrorism
Police have admitted they do not know who Ian Davison intended to target, but are convinced an act of terrorism was in the planning stages.
Det Supt Neil Malkin, who led the investigation, said: "What we uncovered was the fact that he was preparing himself in terms of pipe bombs and purchasing castor beans which are clearly a constituent part of ricin.
"We know he had these very extreme views. We know he was the centre of an extreme right wing group that certainly espoused these views.
"He was purchasing the ricin, we know he had the pipe bomb, he was downloading material that was of use to a terrorist.
"He was very much in the planning stage and we had to take action very quickly to stop it from coming to fruition."
He added: "Certainly this man for me is a terrorist - one of the extreme right wing terrorists. He was well capable of a terrorist act. Yes, it could have led to carnage."