Chemicals supplied by a Bridlington chemist who caused a street to be evacuated were sold to two men who were later prosecuted for terror offences.
Substances sold by trained chemist, Gert Meyers, 55, were found during the course of a police investigation into "extremely serious matters", a court heard.
Police have welcomed the outcome of today's hearing, describing his actions that led 40 homes being evacuated as "irresponsible".
Meyers, 55, of Oxford Street, appeared at Beverley Magistrates' court today (March 29) charged under the Poisons Act for possession of four different chemicals.
District Judge Fred Rutherford said: "What I am told by the Crown is that Mr Meyers was known to the police .
"He has been approached by the police when they were investigating two extremely serious matters - involving a bombing and murder - where substances sold by him were used in the course of those particular acts."
However, he was subsequently cleared on both matters.
Judge Rutherford added: "It leads up to what happens in respect of the matter that he faces now."
On August 4 last year, Meyers was arrested amid a multi agency operation that saw Oxford Street and part of Cambridge Street cordoned off for two days.
Residents had to be evacuated from their homes and the action came at a cost of £36,000 to the taxpayer.
He has today admitted possessing nitric acid, hydrogen peroxide, potassium perchlorate and potassium chlorate — all of which require Home Office approval.
Judge Rutherford said police had warned Meyers on a number of occasions that he must obtain a licence for the substances prior to his arrest.
"As a consequence of further investigations it seems his possession of these substances led to an operation, which in turn made a 200 metre-wide cordon around the area," said Judge Rutherford.
Mitigating, David Robson, said his client had fully cooperated with police and pleaded guilty at the earliest opportunity.
"He was physically ill and couldn't continue his business and his business collapsed," said Mr Robson.
But the judge said Meyers' decision to ignore the police warnings was an aggravating feature.
"He may have cooperated but it seems to me that the aggravating features are such that he is a qualified man, fully qualified in the use and trade of such substances.
"He's been spoken to by the police in respect of the serious nature of the business that he runs. He is warned but he is still in possession of these chemicals," said the judge.
Ordering Meyers to stand, he told him: "As it stands in the circumstances, I feel this matter is too serious for this court and, consequently, you are committed to Crown Court on April 27."
Meyers was granted unconditional bail and was allowed to walk free from court accompanied by a friend.
Speaking after court, Detective Chief Superintendent Matt Hutchinson said: "Gert Meyers legally sold substances to two people who were subsequently prosecuted for terrorism offences.
"This may not have been illegal at the time, however he should have been more responsible for who he was supplying these potentially dangerous substances.
"When the legislation changed he then failed to heed the warnings about the consequences of possessing these substances and is now facing the consequences of his actions and the prospect of a custodial sentence when he is sentenced next month.
"His irresponsible actions led to widespread disruption in Bridlington, whilst emergency services safely removed the volatile substances he was keeping in his home.
"We are committed to keeping the public safe and will take proactive steps to do so like we have in this case.”