Police in Democratic Republic of Congo on Wednesday arrested the president’s chief of staff, Vital Kamerhe, after he testified in an investigation into alleged misappropriation of public funds, a police official said.

Kamerhe, the chief of staff to President Felix Tshisekedi, was being driven by the police to the Makala prison, Sylvano Kasongo, the police chief of the capital Kinshasa, told Reuters.

Tshisekedi’s spokesman, Kasongo Mwema, said he had no comment. “The president does not comment on the decisions of the justice system,” he said.

Tshisekedi came to power in January last year vowing to clean up the corruption that watchdog groups said had flourished under his long-serving predecessor, Joseph Kabila.

Kamerhe has been dogged by allegations of graft over his role in a $304-million public works programme that included roads, bridges and social housing. He has denied all charges of impropriety.