BATAM, INDONESIA: An Indonesian court on Tuesday sentenced two British journalists to two months and 15 days in jail after they were convicted of violating immigration laws by working without appropriate visas.

Neil Bonner and Rebecca Prosser were arrested in May in Indonesia's western island of Batam, where they were filming a documentary about piracy in the Malacca Straits for the London-based production company Wall to Wall, with funding from National Geographic TV.

The two could be freed immediately due to time served.

Foreign journalists must have a work visa to report in Indonesia.

"The defendants have been proven legally and convincingly guilty of committing a criminal offence as foreigners," Judge Wahyu Prasetyo Wibowo said.

Prosser said the guilty verdict made the world's fourth-most populous country a "more dangerous landscape for journalists".

"I feel a sense of sadness because it's journalism on trial and we have been found guilty," Bonner told reporters. "I don't think journalism is a crime."

Last year, two French journalists were convicted of misusing their tourist visas to work as journalists in the politically sensitive Papua province and spent 11 weeks in detention before being sent back to France.

The court also fined the two 25 million rupiah ($1,845) each. The prosecution had asked for a five-month jail term.