London, England (CNN) -- The father of a British sailor who was detained along with his four crew mates by the Iranian Navy last month says the five are being held in Iran but being treated well.
Their vessel, a racing yacht called the Kingdom of Bahrain, was on its way from Bahrain to Dubai for a race when it was stopped by Iranian navy ships on November 25, according to the British Foreign Office.
The boat "may have strayed inadvertently into Iranian waters" when it was intercepted, a Foreign Office statement said.
The five sailors, identified by British government sources as Olly Smith, Sam Usher, Luke Porter, Oliver Young and Dave Bloomer, have now been taken ashore in Iran but are not being held in a prison, Oliver's father, David Young, told reporters.
"They're being well looked after. They've been fed and been treated well," he told ITN.
Young's mother said she was confident her son would cope well with the pressure of the situation. "He will be absolutely fine. He is a very strong person," Susan Young, of Saltash in southern England, told local newspaper, The Herald.
"The team get on really well," she added. "They are a really nice group of lads and I am not worried about their morale or anything like that."
Sail Bahrain, which owns the yacht, said the families of the other crew members have been informed.
Meanwhile, the Reuters news agency reported that an aide to Iranian President Mahmoud Ahmadinejad said Iran will take serious measures against five British yachtsmen detained in the Gulf if it proves they had "evil intentions."
The judiciary will decide about the five...naturally our measures will be hard and serious if we find out they had evil intentions," Esfandiar Rahim-Mashaie, the president's chief of staff, told the semi-official Fars news agency, in quotes carried by Reuters.com.
However British Foreign Secretary David Miliband told Britain's Press Association there was no suggestion that the sailors had any "malicious intent."
"This is a human story of five young yachtsmen," he said. "It's got nothing to do with politics. It's got nothing to do with (Iran's) nuclear enrichment program.
"It's a consular case, which is being treated as a consular case by the UK, and I'm sure will be treated as a consular case by the Iranian authorities.
"It has no relation to any other issue. On that basis, I hope it will be resolved in a speedy and professional manner."
Sail Bahrain is a project inaugurated earlier this month with the objective of bringing international sailing and water sports events to Bahrain and developing a top-class water sports academy.