Jailed Washington Post reporter Jason Rezaian should learn his fate "within a week" after his secretive trial on accusations of spying on Iran ended Monday, his lawyer said.
His newspaper called the trial a "sick brew of farce and tragedy" and said it "has been anything but transparent and just".
The 39-year-old Iranian-American has been in custody more than a year and the allegations were heard behind closed doors, drawing condemnation from his family, employer and press freedom groups.
Outside the court Rezaian's mother read a defiant statement defending her son, saying he was an innocent victim of bad diplomatic relations between Iran and the United States.
- Politically charged case -
The journalist, who has suffered poor health in prison, was "paying the price of the suspicion, the animosity, and the paranoia between the two countries," Mary Rezaian said.
Confirming that Monday's hearing was the last in the case unless there is an appeal, Rezaian's lawyer Leila Ahsan said she had presented her defence and a judgment would follow.
"The verdict will be issued and communicated to us within a week," she told AFP by telephone.
"I expect my client to be acquitted, as he is completely innocent."
Martin Baron, the Washington Post's executive editor, said in a statement "it remains unclear even to Jason's lawyer what might happen next".
"The process has been anything but transparent and just, and that pattern persists. The only thing that is clear is Jason's innocence," he said.
"Now is the time for Iran's senior leaders to end this 'judicial process', with its sick brew of farce and tragedy," Baron said.
The politically charged case unfolded during nuclear talks between Iran and world powers including the United States, which have led to hope of a thaw in ties after decades of strain.
- Wife may face trial -
Iran and America broke off diplomatic relations in 1980, following the Islamic revolution the previous year which led to a hostage crisis at the US embassy in Tehran.
Monday's hearing -- the trial's fourth -- was the first since Iran struck a nuclear deal with the leading powers in Vienna on July 14, and it centred on the reporter's rebuttal of the charges.
He stands accused of "espionage, collaboration with hostile governments, gathering classified information and disseminating propaganda against the Islamic republic."
The charges are thought to carry a maximum penalty of 20 years in prison.
Iran and the United States said there was no linkage between Rezaian's case and the nuclear talks, but President Barack Obama and Secretary of State John Kerry criticised the trial and called for his release.
Ahsan on July 28 said she hoped the recent accord -- in which Iran agreed to curb its nuclear programme in return for the lifting of crippling sanctions imposed by the West -- would hasten her client's freedom.
But repeated bail requests have been refused.
Iran has said the case is a matter for its judiciary and the verdict should not be pre-judged.
The accusations were heard in private at a Revolutionary Court, which usually presides over political or national security cases.
Rezaian, the Post's Tehran correspondent, was arrested with his wife Yeganeh Salehi, also a journalist, at their Tehran home on July 22, 2014.
Although Salehi was released on bail after two and a half months in custody, she has not worked since and is barred from discussing the case.
A photographer arrested on the same day is also out on bail.
No charges have been disclosed against either but Ahsan said she expected court action against Salehi and the other accused after the Rezaian verdict.
Salehi and Rezaian's mother were at court but not allowed inside.
"This case is not about what Jason did. This is a political case, political issues between the United States and Iran," said his mother, who was allowed to visit him last week.
"He is very tired, he is very isolated. Jason's rights as an Iranian citizen have not been fulfilled because he was kept in prison more than one year and many times his trial was delayed.
"I'm challenging those people who arrested him and are trying him, to show the evidence... accusing him of espionage."