In an interview with Business Insider Germany on Thursday, Callamard partially blamed Merkel and French President Emmanuel Macron for the sluggish Saudi investigation.
It was "one thing" when U.S. President Donald Trump behaves like that to Saudi Crown Prince Mohammad bin Salman, Callamard said. However, that "European leaders like Angela Merkel or Emmanuel Macron have joined this travesty" was "unacceptable", she added.
In her official report on the killing of Khashoggi at the Saudi Embassy in Istanbul, Callamard called for an independent investigation into Saudi Arabian government officials, including the crown prince.
A columnist for the Washington Post, Khashoggi was killed and dismembered on Oct. 2, 2018 by a Saudi hit squad in the Kingdom's Istanbul Consulate. His body was never found.