Updated

Guatemalan prosecutors say they've detained the brother and are questioning the son of President Jimmy Morales in a case of alleged corruption.

A U.N. anti-corruption commission says they are suspected of submitting about $20,000 worth of false receipts in an alleged tax fraud.

The president's brother, Samuel, told reporters at the courthouse on Wednesday that he is cooperating with the investigation and said he is innocent.

Attorney General Thelma Aldana says she also sought a warrant for the president's son Jose Manuel Morales Marroquin, but he appeared voluntarily for questioning.

Guatemalan prosecutors backed by the U.N. commission have brought a string of anti-corruption cases, most notably against former President Otto Perez Molina.