A Myanmar journalist arrested in May while covering the aftermath of a deadly cyclone has been jailed by junta authorities for 20 years, his employer said on Wednesday.

The military has waged a sweeping and bloody crackdown on dissent since toppling Aung San Suu Kyi's government in 2021 and at least 170 journalists have since been arrested, according to the United Nations.

Photojournalist Sai Zaw Thaike was jailed for a total of 20 years, according to his employer Myanmar Now.

He had been indicted on four charges, including breaching a natural disaster law and a telecommunications law, Myanmar Now said.

It said it was not clear on what charges he had been convicted.

Myanmar Now editor-in-chief Swe Win said all of Sai Zaw Thaike's colleagues were saddened by the lengthy sentence.

"His sentencing is yet another indication that freedom of the press has been completely quashed under the military junta's rule, and shows the hefty price independent journalists in Myanmar must pay for their professional work," he said in a statement.

Sai Zaw Thaike was arrested on May 23 while covering the aftermath of Cyclone Mocha, which hit western Myanmar's Rakhine state and neighbouring Bangladesh, killing more than 100 people.

He had been held in pre-trial detention since, without access to a lawyer and denied family visits, according to the statement on Myanmar Now's Facebook page

He was sentenced on Wednesday, the first day of his trial, it said.

A junta spokesman could not be reached for comment about the case.

Myanmar Now had its licence revoked shortly after the coup, along with dozens of other local outlets deemed critical of the military.

Security forces had previously raided its office, the outlet said.

More than 24,000 people have been arrested since the coup that plunged the Southeast Asian nation into turmoil, according to a local monitoring group.

Myanmar ranks 173 out of 180 in the latest World Press Freedom Index published by Reporters Without Borders.

According to the watchdog's latest figures, 69 journalists are currently detained in Myanmar.