Zambian opposition leader Chilufya Tayali was late Thursday charged with inciting to mutiny.
Mr Tayali was out on bond following heightened pressure by the opposition and civil society who had been calling for his release after he was detained on Monday.
“Police have formally charged and arrested Chilufya Tayali for the offences of inciting to mutiny contrary to Section 48 subsection (a) of the Penal Code and communication of certain information Contrary to Section 4 (3) of the State Security Act Chapter 111 of the Laws of Zambia,” police spokesperson Rae Hamoonga said in a statement.
If convicted, the politician could face life imprisonment.
Mr Tayali, of the Economic and Equity Party, was picked up on Monday over statements he made about security forces.
During a press briefing in the capital Lusaka, Mr Tayali alleged that the government has not paid military personnel who served in a recent peacekeeping mission.
He is also accused of receiving a classified Zambia Army message in contravention of the State Security Act, and later circulating the document on social media using his Facebook page.
Opposition critics said they are concerned that the country is regressing on its human rights track record despite promises made by President Hakainde Hichilema during his 2021 election campaign that his administration would respect human rights.
Critics said the arrest of opposition members, especially those from the former governing party Patriotic Front, was meant to gag and intimidate them.
Hichilema ran on the ticket of the United Party for National Development.