A senior Bangladeshi woman journalist, known for her investigative reporting, was arrested on charges of violating a colonial-era official secrecy law, the police said on Tuesday, triggering protests by rights groups and her colleagues.

Rozina Islam, a senior reporter of Bangla daily Prothom Alo, the largest newspaper based on circulation, was on Monday detained for over five hours by the health ministry officials for allegedly clicking a picture of a document with her cell phone without permission. She was later arrested by the police.

The ministry filed a case against her at around midnight under the 1923 Official Secrets Act while she spent the night in police custody, the police said.

She was produced before a court here with a petition seeking her to be remanded in custody for five days, which the judge rejected and sent her to jail to await routine legal procedures.

The judge said he would entertain the prosecution charge and the defence statements including her bail petition on Thursday.

A prosecution lawyer said “whether the allegation is true or false, a case has been filed”.