Guatemalan authorities have arrested the country's current and former tax chiefs in a crackdown on a ring that allegedly defrauded the state through corruption and theft.

Prosecutors working in tandem with a U.N. commission against impunity have raided offices and homes and taken at least 20 suspects into custody.

They include Tax Authority director Omar Franco and Carlos Munoz, the agency's former boss.

As Munoz was being taken to a court in handcuffs Thursday he told The Associated Press he did not know why he had been detained.

Prosecutors charge that workers at the Tax Authority accepted bribes in exchange for charging less than the legal tariffs on imports.