Fifteen British sailors and marines freed from captivity in Teheran began two weeks' leave with their families Saturday. The Iranian ambassador to London urged Britain to help Iran mend relations with the international community. Ambassador Rasoul Movahedian told the Financial Times newspaper that Iran had "showed our goodwill" by freeing the Britons. "Now it is up to the British government to proceed in a positive way," he was quoted as saying. "We will welcome in general any steps that could defuse tensions in the region," he added. The British mariners, captured in the Persian Gulf on March 23, were freed Wednesday by Iranian President Mahmoud Ahmadinejad, who called their release a gift to Britain. Movahedian called on Britain to use the resolution of the crisis as a chance to "establish sensible lines of communication with Iran." He said "the prime issue for Iran" was recognition from the West of its right to a nuclear power program. The United States and allies, including Britain, fear Iran is pursuing a nuclear weapons program under cover of its civilian nuclear program. Iran denies this, insisting it seeks to use the program only for nuclear energy. The newspaper said Movahedian spoke before several crew members described Friday how they had been blindfolded, bound, kept in solitary confinement and subjected to psychological pressure during their captivity. They said they were coerced into saying they had been in Iranian waters when they were detained. "All of us were kept in isolation. We were interrogated most nights and presented with two options. If we admitted that we'd strayed, we'd be on a plane to (Britain) pretty soon," said Lt. Felix Carman, who commanded the crew. "If we didn't, we faced up to seven years in prison." Marine Joe Tindell said he believed one of his colleagues had been executed on the second day of the ordeal. The 21-year-old said the crew believed they were being taken to the British Embassy to be released, but were instead dumped in a holding facility. "We had a blindfold and plastic cuffs, hands behind our backs, heads against the wall ... there were weapons cocking," Tindell told British Broadcasting Corp. radio. "Someone said, I quote, 'Lads, lads I think we're going to get executed' ... someone was sick and as far as I was concerned he had just had his throat cut." Iran dismissed the news conference as propaganda - just as Britain had condemned the crew members' frequent appearances on Iranian TV during their captivity. Britain's Foreign Office had no immediate comment on the ambassador's remarks. A spokesman said officials "will need to time to assess the implication for diplomatic relations with Iran" of the crew's accounts of their treatment in detention. The British crew was detained while patrolling for smugglers near the mouth of the Shatt al-Arab, a waterway that has long been a disputed dividing line between Iraq and Iran.