A Russian ex-spy and his daughter may have been exposed to the deadly nerve agent that nearly killed them through his car’s ventilation system, according to a report Sunday.

Former double agent Sergei Skripal and his daughter, Yulia, are still struggling to live after being poisoned with Russian-produced Novichok in Salisbury two weeks ago.

ABC News reported that U.K. officials believe that the toxin was used in a dust-like powdered form and that it circulated through the vents of Skripal’s BMW.

Three intelligence officials said that the Russian military origin and the nature of the “dusty” substance are clear to them, according to the station.

“It is a Cold War substance, something they claimed never to have,” one senior intelligence official told ABC News, referring to Russia.

ABC also reported that intelligence officials said that up to 38 individuals in Salisbury have been identified as having been affected by the nerve agent and that more victims sickened by the agent are expected to be identified.

Also Sunday, the U.K. government said it has evidence Russia has spent the last decade secretly developing nerve agents to use in assassinations in violation of interntional law, The Wall Street Journal reported.

“We have evidence that Russia has been investigating delivery of nerve agents and has been creating and stockpiling Novichok,” British Foreign Secretary Boris Johnson said, according to the paper.

The Associated Press reported that Johnson told reporters Sunday that Britain has information that within the last 10 years, "the Russian state has been engaged in investigating the delivery of such agents, Novichok agents ... very likely for the purposes of assassination."

“We have evidence that Russia has been investigating delivery of nerve agents and has been creating and stockpiling Novichok.”

— British Foreign Secretary Boris Johnson

Johnson added that Russia has “been producing and stockpiling Novichok, contrary to what they have been saying."

Vladimir Chizhov, Moscow's ambassador to the European Union, said Russia has no chemical weapons stockpiles and was not behind the poisoning.

"Russia had nothing to do with it," Chizhov told the BBC.

Chizhov pointed out that the U.K. chemical weapons research facility, Porton Down, is only eight miles from Salisbury.

Asked whether he was saying that Porton Down was responsible, Chizhov replied: "I don't know."

The British government dismissed the ambassador's suggestion as "nonsense."

The Associated Press contributed to this report.