Jason Rezaian, the Washington Post reporter who has been detained in Iran for over a year, has been convicted by a secret Iranian court in an espionage trial and reportedly faces up to 20 years in prison, though it was not immediately clear what Rezaian has been charged with, according to The Washington Post.

Iranian judiciary spokesman Gholam Hossein Mohseni Ejehi confirmed the verdict on state-run TV late Sunday but said he did not have the details and could not specify what punishment the 39-year-old Iranian-American journalist faces. Rezaian has 20 days to appeal the ruling, Ejehi added, according to The Associated Press.

Iranian state TV called Rezaian an "American spy" and accused him of giving information to the U.S. about individuals and companies who were helping Iran get around international economic sanctions, but Rezaian's family and The Washington Post insist the charges are bogus, reports The New York Times.

The Washington Post's executive editor, Martin Baron, called the guilty verdict "an outrageous injustice" and said the newspaper is working with Rezaian's family and lawyer to appeal the decision.

"Iran has behaved unconscionably throughout this case, but never more so than with this indefensible decision by a Revolutionary Court to convict an innocent journalist of serious crimes after a proceeding that unfolded in secret, with no evidence whatsoever of any wrongdoing," he said in a statement.

Iranian President Hassan Rouhani recently suggested that a prisoner swap may eventually be possible, in which three Americans held in Iran could be exchanged for Iranians being held in the U.S. for violating sanctions, according to USA Today.

The U.S. State Department, which has not had formal diplomatic ties to Iran since the 1979 hostage crisis, told the Post that U.S. officials have not received confirmation or details from the Iranian government about the charges.

"We continue to closely track the news coming out of Iran concerning the trial of U.S. citizen Jason Rezaian," said State Department spokesman John Kirby. "We've seen news reports that Jason has been convicted, but we still have not seen any official confirmation of a verdict on specific charges or any further information. Unfortunately, this is not surprising given that this process has been opaque and incomprehensible from the start. Regardless of whether there has been a conviction or not, we continue to call for the government of Iran to drop all charges against Jason and release him immediately."