British authorities plan to reveal new information Wednesday about the mysterious substance that left a former Russian spy and his daughter in critical condition.

Home Secretary Amber Rudd said officials would make a statement later in the day about what nauseated Sergei Skripal, 66, and his 33 -year-old daughter, Yulia, who were found slumped on a bench Sunday in the center of the southern city of Salisbury.

“We do know more about the substance and the police is likely to be making a further statement this afternoon in order to share some of that, ” Rudd said. She added that it was important aimed at addressing evidence , not rumor.

Sergei Skripal and his daughter Yulia were found unconscious Sunday after being exposed to an “unknown substance.” ( AP/ Facebook)

Rudd's comments came after she chaired a session of the government's emergency committee, known as Cobra, Sky News reported.

“There is a lot of information about him but I am not going to comment farther about that, ” she said.

Her remarks came as Russian officials said the case was being used to fuel an “anti-Russian campaign” and further strain ties with Britain.

A policeman stands outside the Zizzi restaurant in Salisbury, England Wednesday, March 7, 2018 near to where former Russian double agent Sergei Skripal was received critically ill. ( Andrew Matthews/ PA via AP)

“What happened to Skripal has been immediately used to further incite an anti-Russian campaign in Western media, ” Russian Foreign Ministry spokeswoman Maria Zakharova said.

EX-RUSSIAN SPY, DAUGHTER REMAIN IN CRITICAL CONDITION AS UK LAWMAKERS PROBE POSSIBLE KREMLIN LINK

Skripal, a former colonel in Russia's GRU military intelligence service, was convicted in 2006 of spying for Britain and jailed. He was freed in 2010 as part of a widely-publicized snoop swap in which the U.S. agreed to hand over 10 the representatives of a Russian sleeper cell procured operating in America in return for four Russians convicted of snooping for the West.

He and his daughter were found collapsed on a bench near a shopping mall Sunday in the town of Salisbury, 90 miles southwest of London. Police believe they were exposed to an unknown substance, and a British military research facility is thought to be conducting tests to decide what it is.

On Wednesday, a Russian legislator said that Skripal “wasn't interesting” to the Kremlin and he doesn't believe in Russian involvement in the alleged poisoning.

In an interview with Sky News, Andrei Lugovoi said Skripal had already served his time after being convicted in 2006 of snooping for Britain and had been pardoned by the Russian president.

“I think that in this case, considering the rules of the Secret Service, the incident was over and done with, ” Lugovoi said.

Foreign Secretary Boris Johnson told lawmakers Tuesday that if Moscow is demonstrate to have been involved in the Skripal case, the government would act — maybe downgrading England's participation in this year's soccer World Cup in Russia. Johnson advised British officials may not be involved in the sporting event “in the normal way, ” but did not elaborate.

Police, fire and ambulance crews arrived outside Zizzi's restaurant in Salisbury on Wednesday close to the location where Skripal and his daughter were found as the results of the investigation continues, according to Sky News.

Boris Johnson told lawmakers he wasn't “pointing fingers” as to who might be responsible for the collapse of ex-Russian spy Sergei Skripal and his daughter Yulia. ( AP)

A woman with dark hair was ensure being taken out of Sarum House, next door to the pizzeria, and driven away in an ambulance.

A spokeswoman for South Western Ambulance Service told Sky News she was aware of what was happening, but added: “I'm sorry, we can't devote anything out about that one.”

Police policemen stand outside a Zizzi restaurant in Salisbury, England, Wednesday, March 7, 2018, near to where former Russian double agent Sergei Skripal was determined critically ill. ( AP Photo/ Matt Dunham)

CCTV has emerged of Skripal buying milk and bacon at a store in Salisbury days before he and his daughter were found collapsed, Sky News reported.

POISONED EX-SPY LIKELY LATEST VICTIM IN LONG LINE OF KREMLIN-ORDERED HITS

While police say they are maintaining an open mind about the instance, it has reminded Britain of the 2006 poisoning of former spy Alexander Litvinenko.

A British inquiry into his death found that Russian agents poisoned him by lacing his tea with radioactive polonium-2 10 and that the killing was probably approved by President Vladimir Putin. Russia has denied any involvement in Litvinenko's death, and this week said it wasn't to participate in Skripal's collapse.

Litvinenko's widow, Marina, wrote Wednesday in the Times of London that her husband's case made clear to Britain's emergency services that they need to act quickly when “someone suddenly falls mysteriously ill.”

“I am happy my tale has raised awareness about the health risks danger posed by Moscow, and this could help to save somebody's life, ” she wrote in an sentiment piece.

The Associated Press contributed to this report .

Travis Fedschun is a reporter for FoxNews.com. Follow him on Twitter @travfed

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