Hunt said Russia should not use British citizens in "diplomatic chess games" after a former US marine with dual citizenship was detained for suspected spying.
British diplomats were assisting 48-year-old US resident Paul Whelan, who was born in Canada to British parents, Hunt told Sky News during a visit to Singapore.
Whelan's family said he was arrested in Moscow during a visit to attend the wedding of another former marine, the broadcaster said.
Hunt said he was "extremely worried" about Whelan, adding that "individuals should not be used as pawns of diplomatic leverage."
"We are giving him every support that we can, but we don't agree with individuals being used in diplomatic chess games," he said.
Russian foreign ministry spokeswoman Maria Zakharova told the TASS news agency in Moscow on Friday that Britain had requested consular access to Whelan, confirming that he was detained on suspicion of spying.
"The British side has sent a request for a consular visit. Work on it is in progress," Zakharova was quoted as saying.
The Russian Federal Security Service (FSB) said it had opened a criminal investigation after detaining Whelan on December 28 while he was "on a spy mission," the agency reported.
It said Whelan, who was visited by US Ambassador to Russia Jon Huntsman on Wednesday, could face between 10 and 20 years in prison if he is convicted of spying.
British diplomats were assisting 48-year-old US resident Paul Whelan, who was born in Canada to British parents, Hunt told Sky News during a visit to Singapore.
Whelan's family said he was arrested in Moscow during a visit to attend the wedding of another former marine, the broadcaster said.
Hunt said he was "extremely worried" about Whelan, adding that "individuals should not be used as pawns of diplomatic leverage."
"We are giving him every support that we can, but we don't agree with individuals being used in diplomatic chess games," he said.
Russian foreign ministry spokeswoman Maria Zakharova told the TASS news agency in Moscow on Friday that Britain had requested consular access to Whelan, confirming that he was detained on suspicion of spying.
"The British side has sent a request for a consular visit. Work on it is in progress," Zakharova was quoted as saying.
The Russian Federal Security Service (FSB) said it had opened a criminal investigation after detaining Whelan on December 28 while he was "on a spy mission," the agency reported.
It said Whelan, who was visited by US Ambassador to Russia Jon Huntsman on Wednesday, could face between 10 and 20 years in prison if he is convicted of spying.