"Extreme action" will be taken if a Scottish man arrested in India has been tortured by police, a Foreign Office minister has suggested.

Rory Stewart told MPs the UK Government was working closely to investigate the case of Jagtar Singh Johal, from Dumbarton in West Dunbartonshire, who was detained in Jalandhar in the state of Punjab on November 4.

Campaigners say Mr Johal, 30, has been tortured by police and Mr Stewart said the government would "take extreme action if a British citizen is being tortured".

During Foreign Office questions in the Commons, the SNP MSP for West Dunbartonshire Martin Docherty-Hughes raised his constituent's case.

He asked: "Can the secretary of state advise me and the House how he's working with the office of the Prime Minister to assist my constituent and his family in Dumbarton?"

Mr Stewart said the case was being taken very seriously.

He told MPs: "The Deputy High Commission managed to gain access - we have now had a meeting with the constituent.

"We take any allegation of torture very seriously, as indeed would the Indian government.

"It is completely unconstitutional - it is offensive to the British government - and we will work very closely to investigate and of course will take extreme action if a British citizen is being tortured."

The Sikh Federation UK says no official charges have been brought against Mr Johal but local media reported his arrest was linked to the killing of Hindu leaders in Punjab.

The organisation said Mr Johal moved to judicial custody after appearing in court in Punjab earlier this month, sparking hopes the "physical torture" will come to an end.

He was later returned to police custody without charge.