Over 500 protesters have gathered outside the administrative headquarters of Ukraine's president to call for the resignation of the country's general prosecutor, who they say, has failed to use the full power of his office to deal with endemic corruption.

Monday's protest comes after a Kiev court gave the prosecutor's office, which is run by Viktor Shokin, full rein to investigate one of its toughest critics, the Anti-Corruption Action Center, over claims that the watchdog embezzled $2.2 million in aid.

Under the terms of the warrant, the general prosecutor's office can seize documents and access confidential bank information.

The Anti-Corruption Action Center has described the charges as politically motivated. The U.S. Ambassador to Ukraine has also raised concerns.

President Petro Poroshenko appointed Shokin as general prosecutor in February 2015.