Detained Malagasy investigative journalist Fernand Cello is expected to appear in court on Monday, local media reported.
Mr Cello will appear in court at Ihosy in Ihorombe Region in central south Madagascar.
He was arrested in the capital Antananarivo on Friday evening, just two days after the World Press Freedom on May 3.
The journalist was reportedly forcibly removed from the private clinic where he had sought medical treatment.
"Seven men in civilian clothes took him away on Friday at 7pm 15 (local time) while he was still in hospital," one of Mr Cello's brothers posted on Facebook.
Mr Cello had on May 3 vehemently denounced on TV irregularities in one of the private mining companies operating in Ilakaka's area, where about half the world's sapphire was extracted annually.
Malagasy journalists have condemned Mr Cello's arrest and the general assault on the freedom of expressions in the country.
He was sick
In a press release on Saturday, the Madagascar journalists union (OJM) announced its determination to defend Mr Cello if his arrest was occasioned by his journalism practice.
"We urge the authorities to consider his state of health as he was sick when he was arrested," the OJM statement said.
Unconfirmed reports said Mr Cello was being accused of seven charges unrelated to his journalistic practice.
Mr Cello is well known for his outspokenness and courage.
He was previously the manager of the Ilakaka-based private-run Radio Jupiter, whose premises the police stormed and vandalised last August.
Earlier in February 2016, unidentified men seriously injured him at his residence.