Jakarta – Indonesia's high-profile anti-corruption czar has been named a suspect over the murder of a state company executive, officials said.

Corruption Eradication Commission (KPK) head Antasari Azhar was formally declared a suspect in the drive-by shooting murder of company executive Nasrudin Zulkarnaen late Friday, the Attorney General's Office said.

Police had no comment about the allegations against Antasari, who has headed a strong crackdown on corruption including a series of investigations into prosecutors at the Attorney General's Office, which have proved damaging for officials and institutions involved.

His lawyer said Antasari would be questioned as a witness over the murder of Zulkarnaen, the director of state firm Putra Rajawali Banjaran, who was shot on the outskirts of Jakarta on March 14.

He said Antasari had requested "temporary leave" from his KPK duties to attend to the allegations. The corruption fighter and former prosecutor was one of Zulkarnaen's golfing friends.

Since its establishment in 2003, the independent KPK has gained a reputation as one of the few clean institutions in the country, one of the most corrupt in the world according to Transparency International.