Khawar Mahdi Rizvi and two others were produced before a judicial magistrate on Tuesday in the southwest city of Quetta, capital of Baluchistan province.
"He was produced before the judicial magistrate and the magistrate remanded him to police custody for investigation," a Baluchistan police official said on Wednesday.
Rizvi was arrested on 16 December with reporters Marc Epstein and photographer Jean-Paul Guilloteau of France's L'Express magazine because the French pair had violated their visa restrictions by travelling to Quetta.
The French journalists were jailed, charged, tried and sentenced to six months' prison and eventually freed this month on appeal, although their visa violation convictions were upheld.
They flew home on 13 January.
Rizvi, Syed Allah Noor and Abd Allah Shakir have been charged with sedition, criminal conspiracy and impersonation for allegedly preparing a film of a fake Taliban training camp between Quetta and the Afghan border.
Epstien (L) and Guilloteau were
held for visa violation
Rizvi, a freelance journalist, had accompanied the French journalists to Baluchistan, where Afghanistan's Taliban had emerged in 1994.
Rizvi's whereabouts had been a mystery for about five weeks as authorities denied he was under detention, although state-run television had shown him in police custody soon after his arrest.
"I am really mentally tired and suffered a lot and today I saw the sky after weeks in police custody," Rizvi told reporters at the court.
International rights group and media organisations have slammed Rizvi's arrest.
Pakistan Television had shown footage, allegedly seized from the French journalists, in which Nur and Shakir were seen training a small group of young men in the use of weapons.
The film showed Shakir posing as Taliban commander Mullah Malangi, police said.
The accused face a maximum punishment of 10 years' in jail.