Iran has denied allegations that Michael White has received poor treatment in jail (AFP)
Iran on Wednesday confirmed a US media report that an American military veteran was arrested last year, but denied he had been badly treated.
"A US citizen called Michael White was arrested some time ago in Mashhad and the US government was informed of this in the first days of the arrest through the US interest section in Tehran," said foreign ministry spokesman Bahram Ghasemi on his Telegram channel, AFP news agency reported on Wednesday.
The New York Times reported on Monday that White, a 46-year-old US Navy veteran, was arrested while visiting Iran and had been held since July 2018 on unspecified charges.
White's mother, Joanne, told the New York Times her son had visited Iran "five or six times" to meet his Iranian girlfriend.
She reported her son's disappearance after he failed to return in July but learned from the State Department only three weeks ago that he was being held in Iran.
The US State Department said on Tuesday it was "aware of reports" of his detention but declined to release details, citing privacy considerations.
London-based news website IranWire, which first reported White's arrest, quoted a former detainee, Ivar Farhadi, as saying he had been held at the same prison, Vakilabad, in Mashhad, northeastern Iran.
Farhadi told IranWire White's life was in danger because he was being kept in a prison with dangerous criminals.
Ghasemi said reports in the US media that White was being held in poor conditions were "false and are strongly denied".
White's case is going through the legal process and officials will make a statement at the appropriate time, Ghasemi added.
US interests are handled by the Swiss embassy in Tehran, as the two countries have not had diplomatic relations since 1980.
White joins at least three other US citizens, two of them of Iranian descent, in Iranian detention.
Relations between Iran and the US deteriorated sharply last year when President Donald Trump withdrew from an international accord on Iran's nuclear programme and re-imposed sweeping sanctions.