Updated

Brazil's federal police announced Thursday that they are shutting down the primary task force assigned to a mammoth corruption investigation, drawing criticism from prosecutors who said it would undermine the probe.

The investigation, known as "Operation Car Wash," is Brazil's largest-ever corruption probe. It has jailed top politicians and business executives and led to allegations against President Michel Temer.

Officers from the task force based in the southeastern city of Curitiba will be folded into an already existing division that investigates corruption, federal police announced.

The move has important symbolic significance since the investigation has been led by the task force, along with prosecutors and judges in Curitiba. Coming just months after a reduction in the size of the task force, the elimination of the dedicated group of investigators has again raised concerns that authorities are trying to stifle the probe.

The decision means the officers will no longer focus exclusively on Car Wash cases. Prosecutors assigned to the probe called it "an obvious step backward," saying investigators were already struggling to keep up with the workload.

"The number of inquiries and investigations is restricted by the number of available investigators," the prosecutors said in a statement. "There is a long list of pending material to analyze and the police officers on the case aren't able to develop new lines of investigation."

The federal police force tried to head off criticism by saying that it "reaffirmed the public commitment to combat corruption" and that officers would not see their workload increase. It also said there were enough officers to respond to the demands in the Curitiba office.

In May, prosecutors and police complained when the task force's size was cut, saying it would make their jobs harder. The prosecutors' Thursday statement noted pointedly that Temer's government was responsible for the cuts in May and the end to the task force.