The British media said on Wednesday that Andrew Neal, 44, had been arrested at his home in Dubai on 4 October for involvement in drug dealing.
The reports said, however, that the former military serviceman, who received 17 medals during 24 years in the army and had been discharged for suffering mental problems during the Afghan war, had been forced to sign false confessions, Presstv Reported.
A group of legal campaigners, said they had evidence that could show UAE authorities had mistakenly arrested Neal in Dubai, adding that he should be released immediately.
The UK foreign ministry, the Home Office, said it was aware of the arrest and in touch with the UAE authorities over the issue.
The arrest is the third such case involving British nationals in the UEA in recent months. Reports earlier this month said a British man had been arrested for expressing sympathy for the Qatari national team during the Asian Cup football tournaments held in the Persian Gulf country.
The UAE embassy in London denied that the arrest of Ali Issa Ahmad had anything to do with his wearing of Qatari team’s shirt, saying the British man was under custody for wasting police time and making false statements.
In November, UAE authorities said a court in the country had sentenced Mathew Hedges, a British academic, to life in prison over espionage charges. Hedges was released later that month after the UK government threatened the case could harm bilateral ties.