Chen has been in custody since December 30 as a suspect, but has consistently proclaimed his innocence and accused the judiciary and the government of violating his human rights.

The Taipei District Court panel of judges Tsai Shou-shun, Wu Ting-ya and Hsu Chien-huei has repeatedly extended Chen’s custody, arguing the former president presents a flight risk and could influence witnesses and defendants.

Chen’s cases were initially handled by another three-judge panel, which ordered his release late last year. The court later handed the ex-president’s cases over to the new panel, which followed prosecutors’ requests to keep Chen in custody.

Chen’s attorney Ho Chao-tung filed the suit against the three judges at the Taipei District Court Wednesday, reports said. The judges had not taken the law into consideration but used custody as an instrument of revenge, punishment and humiliation against Chen, a statement from his office said.

The three judges had obtained control over Chen’s case in an unconstitutional manner, the statement said, and were now using false pretenses to keep him in jail. They accused him of interfering with the course of justice because he pleaded innocent, held hunger strikes, published books and gave an interview to a foreign reporter, Chen’s office said.

The former president’s legal problems exploded into the open in August last year, when a magazine published allegations of money laundering. Since then, Chen and a wide range of close relatives, former aides and government officials, and prominent business people have been indicted on charges ranging from misusing special government funds and accepting bribes to laundering money overseas.

The same three-judge panel sued by Chen Wednesday is scheduled to announce a verdict in his cases on September 11.