Moscow has denied that a former US marine is being held as a bargaining chip for a jailed Russian spy, after Jeremy Hunt warned against using Britons as pawns.

Paul Whelan, 48, who has UK citizenship, was arrested in the Russian capital last week, apparently on espionage charges.

There has been speculation that he could be used to barter for the release of a Russian citizen jailed in the US, after she admitted acting as a secret agent for the Kremlin.

The foreign secretary said the UK was giving Whelan “every support we can” and added that Moscow should not use people as pieces in “diplomatic chess games”.

But on Saturday, Russian news agencies quoted the country’s deputy foreign minister, Sergei Ryabkov, as saying it is too early to talk of the “possibility of exchanges”, as Whelan was yet to be formally charged.

Interfax reported that he said “there is no connection” with the case and any Russian citizen in the US.

The arrest of Whelan, who lives in Michigan, comes after Maria Butina, a Russian national, pleaded guilty to conspiracy charges in the US last month.

She admitted conspiring to infiltrate the US gun rights movement to collect intelligence on conservative political groups as Donald Trump rose to power.

Hunt told Sky News that “individuals should not be used as pawns of diplomatic leverage”.

He added: “We are giving him every support that we can, but we don’t agree with individuals being used in diplomatic chess games.”

Whelan’s brother David said his “innocence is undoubted and we trust that his rights will be respected”.

The man’s detention comes as tensions between the UK and Russia are strained.

The Russian president, Vladimir Putin, rejected British claims that the Kremlin was behind the nerve agent poisonings in Salisbury last year.

Relations were further harmed by testimony during a recent Old Bailey inquest linking Russia with the death of the UK-based multimillionaire Alexander Perepilichnyy.

He had been due to testify about serious organised crime in Russia.

Moscow is having to deal with four countries over Whelan’s detention because he is also a citizen of Ireland, Canada and the US.

According to his brother, Whelan was in Moscow to help plan a fellow former US marine’s wedding because he had visited Russia several times previously.