Two French journalists freed from prison in Pakistan say they are worried about the fate of a Pakistani journalist who was arrested with them.
The French journalists spent seven days in jail
Reporter Marc Epstein and photographer Jean-Paul Guilloteau were speaking on their arrival in Paris after being released on Tuesday.
Reports say Khawar Medhi Rizvi is being held at an undisclosed location.
All three were detained after travelling to the city of Quetta, close to the Afghan border.
The two French journalists told fellow reporters that they knew nothing about what had happened to Mr Rizvi.
"What worries us today is the fate of our colleague and friend Khawar Mehdi Rizvi, of whom we have had no news for a month now," Mr Epstein said.
"We don't know where he is."
Some reports say a court will hear Mr Rizvi's case next week.
However, no information has been released on what charges he may face. And it is not clear which branch of Pakistan's security forces is holding him.
Paris-based media watchdog, Reporters Without Borders, has condemned what it says is an obvious breach of the law.
It says it fears Mr Rizvi may have been maltreated since his arrest.
The two French journalists, who work for the weekly L'Express, and Mr Rizvi were arrested by the Pakistani authorities last month.
A court subsequently sentenced the French men to six months in prison after ruling that they had visited Quetta, in south-western Pakistan, without permission.
Their term was reduced to seven days after lawyers filed an appeal.
Since the two journalists had already spent that long in the prison, they
were set free on Tuesday.
The court increased the fine against the journalists from $1,750 to $3,500
Police said the Frenchmen's visas only allowed travel to Islamabad, Lahore
Pakistani security officials alleged that the Frenchmen were trying to
portray some local armed tribesmen as Taleban during their stay in Quetta in
December, but the allegation was not raised in court.