After being held for 40 days in Iran, a Hingham native and Boston University graduate has arrived back in the United States.

Matt Trevithick, 30, was freed from Tehran’s notorious Evin Prison on Saturday after Secretary of State John Kerry pressed the Iranians for his release, according to a State Department official who spoke to the Boston Globe.

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Trevithick was imprisoned without U.S. officials being notified, and the reason for his detainment remained unclear on Sunday when he arrived in Boston, the State Department source said to the Globe.

While he was still en route back to Boston, his mother said to CBS, “We’re very excited. We were happy to hear Matt’s voice today. We are thrilled he is out of Iran.”

After graduating from Boston University in 2008, Trevithick had spent four years in Afghanistan and Turkey before going to Iran in September for a language-intensive university program, CBS added.

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Trevithick was released simultaneously with four Americans who had been held by the Iranian regime, including a Washington Post reporter and a Marine veteran, the Boston Globe stated.