Naypyidaw, Myanmar (CNN) Myanmar's top court rejected the appeal of two Reuters journalists to have their convictions and seven-year prison sentences overturned on Tuesday, in a case that has raised fears over shrinking press freedoms in the country.

Wa Lone and Kyaw Soe Oo have been locked up since December 2017, when they were charged under the country's colonial-era Official Secrets Act for allegedly disseminating secret information sensitive to national security.

They had been investigating the killing of Rohingya Muslims in Myanmar's far west. Earlier this month, the pair were awarded the Pulitzer Prize for International Reporting, one of journalism's most prestigious prizes.

In September 2018, a court convicted the two Myanmar nationals and sentenced them to seven years in prison . Earlier this year, the High Court in Yangon rejected their appeals

The Supreme Court judge again denied their appeals without comment or explanation.

Journalists Kyaw Soe Oo, left, and Wa Lone, right, being escorted by police after their sentencing by a court to jail in Yangon on September 3, 2018.

Defense Lawyer Khin Maung Zaw said that Wa Lone and Kyaw Soe Oo would not lodge further appeals. The pair would instead hope for a presidential pardon, he said.

"The verdict was also a huge barrier for the press freedom," Khin Maung Zaw said. "The verdict would impact the international community. That is why we tried our best for the image of the country."

The pair were not present in court for the latest ruling. Wa Lone's wife Pan Ei Mon told media she was unhappy with the result.

"It's very sad (that) what we expected didn't happen," she said.

'Victims of a police set up'

After the verdict, Reuters Chief Counsel Gail Gove said in a statement the pair had not committed any crime.

"They were victims of a police set-up to silence their truthful reporting. We will continue to do all we can to free them as soon as possible," Gove said.

American non-profit group the Committee to Protect Journalists called the rejected appeal a "grave injustice."

"They should both be free and able to continue their reporting, not sitting in jail cells," said CPJ Senior Southeast Asia Representative Shawn Crispin in a statement . "Their conviction and sentence will be an enduring stain on Myanmar's reputation."

Chit Su Win, second right, the wife of jailed Myanmar journalist Kyaw Soe Oo grieves with family members outside the court on September 3, 2018.

The case was seen as a litmus test for press freedom and democratic rights in the Southeast Asian country. The jailing of the two journalists cast a pall over Myanmar's media community and sparked increased international criticism of the nation's de facto leader and Nobel laureate Aung San Suu Kyi.

The men led an explosive Reuters investigation into the killing of 10 Rohingya men in the village of Inn Dinn -- part of a military-led campaign against the Muslim minority which began in August 2017 after Rohingya militants attacked police posts.

More than 720,000 Rohingya are estimated to have been forced to flee into Bangladesh as a result of the ensuing violence.

As the military in the mainly Buddhist nation tore through Rakhine state, allegedly killing with impunity, raping women and burning babies alive, authorities turned on the reporters trying to investigate the atrocities.

Wa Lone and Kyaw Soe Oo say they were set up by a police officer posing as a source. They say that in late 2017, officers invited them to a secret meeting at a restaurant on the outskirts of Yangon and handed them documents.

Police swooped and arrested them with the classified information in their possession.

The Myanmar government denies human rights abuses by the military in 2017, saying it was targeting Rohingya militants.