A leading Bangladesh publisher has been charged under controversial digital security laws for associating with someone suspected of spreading fake news about the prime minister and her son, an official said Wednesday.

Nur Mohammad, the owner of Guardian Publications, was arrested by police at his office in the capital on Monday, the company's deputy managing director, Mahmudul Hasan, told AFP. "He has been charged under the country's Digital Security Act," he said.

Journalists and rights activists say the Digital Security Act passed in 2018 is a serious threat to freedom of expression in the nation of 168 million people. Under the Act, anyone can face a life jail term for "propaganda" against the nation and up to 10 years for digital content that "hurts religious sentiments" or "creates unrest".

Odhikar, a rights group, reported at least 29 arrests last year under the law. Nur Mohammad's arrest came after Guardian Publications was blocked from taking part in the country's largest annual book fair, which takes place this month.

Guardian Publications is a leading publisher of literature about Islamic philosophy, religion, Bangladeshi culture and history. The company has published two books by Pinaki Bhattacharya, a leading critic of Prime Minister Sheikh Hasina.

Bhattacharya, who fled the country for France last year after security forces allegedly raided his home, condemned Mohammad's arrest and called for his release.