KINSHASA (Reuters) - Vital Kamerhe, the chief of staff to the president of Democratic Republic of Congo, was arrested on Wednesday after testifying in an investigation into the alleged misappropriation of public funds, police said.

FILE PHOTO: Vital Kamerhe, leader of the Union for the Congolese Nation (UNC) party, attends a meeting with Congo's Independent National Electoral Commission (CENI) and observers from the Southern African Development Community(SADC) in Kinshasa, Democratic Republic of Congo, December 28, 2018. REUTERS/Baz Ratner/File Photo

Kamerhe’s arrest was a blow to President Felix Tshisekedi, who took power in January last year after campaigning on promises to clean up corruption, which watchdog groups said flourished under his long-serving predecessor, Joseph Kabila.

Tshisekedi’s spokesman, Kasongo Mwema, said: “The president does not comment on the decisions of the justice system.”

The arrest followed hours of testimony at the public prosecutor’s office. Outside, police used tear gas to disperse a large group of Kamerhe’s supporters and enforce a ban on meetings of more than 20 people in response to the coronavirus pandemic.

His supporters also protested in his hometown, Bukavu, in eastern Congo, where about 300 of them burned tyres and blocked the road outside his party headquarters.

After the testimony, Kamerhe was driven by police to the Makala prison, Sylvano Kasongo, the police chief of the capital, Kinshasa, told Reuters.

It was not immediately clear how long Kamerhe would be held or whether he would be charged with a crime. Reuters was not immediately able to contact his lawyer. Kamerhe has denied all allegations of impropriety.

Tshisekedi has touted his efforts to root out endemic corruption in Congo, but activists have criticised his government’s spending on a $304 million public works programme as lacking transparency.

Kamerhe, in particular, has faced scrutiny for his role in the spending on roads, bridges and social housing.

Kamerhe’s Union for the Congolese Nation (UNC) party joined forces with Tshesekedi’s Union for Democracy and Social Progress (UDPS) in the run-up to the December 2018 election. Tshisekedi promised to back the UNC’s candidate in the next election in 2023.

The arrest could cause the collapse of the coalition, but that may have already been in the cards, said Jason Stearns, director of the Congo Research Group at New York University.

“The coalition was important ahead of the elections, but ever since he was inaugurated, there have been people around Tshisekedi pushing him to get rid of Vital,” Stearns said.