Russian opposition leader Aleksei Navalny says he is filing official complaints contending that Moscow police are not investigating an attack against him.
Navalny wrote on his website on May 2 that he had lost 80 percent of the sight in his right eye after an assailant splashed a green antiseptic known as "zelyonka" on his face outside the office of his Anticorruption Foundation on April 27.
He said his doctor believes there was also a second corrosive substance in the liquid that was used in the attack, but that "there is hope" that the lost eyesight will be restored.
Navalny also alleged that the attacker was Aleksandr Petrunko, a man he said had ties with State Duma deputy speaker Pyotr Tolstoi.
He claimed the assailant had help from Aleksei Kulakov, who he said was a police officer in civilian clothes, and possibly from two other men captured in images from the scene.
There was no immediate comment from the police on Navalny's allegations.
Navalny is seeking to run for president in March 2018 -- a direct challenge to President Vladimir Putin, who is widely expected to seek and secure a new six-year term.
Russian authorities say Navalny will be barred from the ballot if a conviction on financial-crimes charges is upheld on appeal. He denies wrongdoing and has vowed to press on with his campaign.