Nine people have said Donald Trump’s national security advisor did in fact discuss Barack Obama's Russia sanctions with the country before the inauguration – contradicting what he said earlier this week.

The current and former officials claim Mike Flynn explicitly discussed the sanctions on the Kremlin with the Russia ambassador to the US, Sergey Kislyak – although a spokesperson for Mr Flynn said he couldn't remember if the issue of sanctions was discussed.

That is despite Mr Flynn twice saying “no” in an interview this week when asked if the sanctions, over Russia’s interference in the US election, were talked about.

Some officials told The Washington Post that Mr Flynn's actions are potentially illegal and inappropriate.

“Kislyak was left with the impression that the sanctions would be revisited at a later time,” said one former official.

Various counterintelligence officials have already investigated Mr Flynn over his communication with Mr Kislyak in the month before Mr Trump’s inauguration on 20 January.

The retired lieutenant general allegedly spoke to Mr Kislyak on the telephone five times over, on 29 December; the same day Mr Obama expelled 35 Russian diplomats from the country.

Two Russian compounds in the US were also closed in retaliation to cyber-attacks on the Democratic National Committee (DNC), Hillary Clinton’s campaign and other political organisations.

Two of the nine officials say Mr Flynn urged Russia not to overreact to the penalties because the situation would be reassessed after Mr Trump was sworn in.

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Officials say the FBI is continuing to investigate the communications.

Despite Mr Flynn’s denial on Wednesday, a spokesman for the 58-year-old backtracked on Thursday.

The spokesman said Mr Flynn “indicated that while he had no recollection of discussing sanctions, he couldn’t be certain that the topic never came up”.