The partner of a Scottish anti-piracy guard jailed in India fears he could be forgotten the longer his ordeal goes on.

Former soldier Billy Irving, from Connel, Argyll and Bute, is one of the so-called Chennai Six, a group of British ex-servicemen detained since 2013 on firearms charges after their anti-piracy ship strayed into Indian waters.

Customs officials boarded the vessel and found 35 guns, including semi-automatic weapons and almost 6000 rounds of ammunition.

Charges against the men, who were working for the American firm AdvanFort, have since been dropped but they have been unable to leave while prosecutors pursue an appeal.

Mr Irving's fiancee, Yvonne MacHugh, has now revealed that she fears he will be forgotten as they continue to wait for an appeal decision that could allow him to return home for the first time in almost four years.

Ms MacHugh is travelling to visit him in prison where he is being held with the five other Britons and dozens of men of other nationalities charged with possessing weapons illegally.

She told STV News: "This has ruined so many lives. A lot of our friends have really been affected by this. It's a horrible thought to think: who knows when he could be back?

"There's always room for optimism and I'm always hopeful that something is going to happen. Every time we get told it could be next week [that he will be released] I'm still thinking 'this is it, he's coming home'.

"There's been so many diplomatic meetings that we've just clung on to with the hope that this is it, this will be the deal breaker, they will release them but there's still nothing three-and-a-half years on.

"I feel like the men could be forgotten the longer this goes on. The less it's in the public eye and the less people know about it; they will just be forgotten and left in there until such time as the Indian government decides, OK we can send them home now."

India's prime minister Narendra Modi last year assured PM Theresa May he is "closely" following Mr Irving's case.

During almost three hours of talks in New Delhi in November, Mrs May told Mr Modi the plight of the Chennai Six was "a case of concern" in the UK.

British sources said Mr Modi assured Mrs May he was aware of UK concerns. He pledged to consider what could be done by the two governments once the current appeal process has concluded.

The jailed men say they were conducting legal anti-piracy work, protecting merchant ships in international waters.

Ms MacHugh continued: "Every time I go to India I just sit on the plane and dream about it and imagine Billy coming home.

"There was a time when every time I went out I thought that was going to happen.

"Now, I just can't see it happening this time.

"It's extremely frustrating - you're worrying daily about their health. We're getting no phone calls so the last time I spoke to Billy was when I was in prison visiting him in June.

"All we've got is letters back and forward and you can't get a feel for how somebody is physically, or how they are mentally, through a letter. All you've got is what they've written down at that time.

"We've got no real communication with the Indian government or the Indian police or our Indian lawyer.

"There's been nothing from the Foreign Office about the visit with Mr Modi. They let us know there was a meeting but we don't know what was said."