Morocco on Tuesday arrested human rights activist Maati Monjib after an investigation over money laundering, a security source said.
Monjib, 60, was brought before the attorney general at Rabat's court of first instance, the source at the General Directorate for National Security (DGSN) told AFP.
He was later referred by the prosecution to an investigative judge before being ordered into pre-trial detention at Rabat's El Arjat prison.
The prosecution said it launched a probe in October after the seizure of evidence pointing to money transfers and real estate assets beyond the means of Monjib and his family.
The historian said on Facebook that the information was "not new" and had already been part of a trial for "financial embezzlement" and "undermining state security" which opened in 2015.
"I am innocent of all these defamatory accusations," he wrote.
Monjib is being prosecuted along with six other human rights activists and journalists in a trial that had been scheduled to begin in 2015.