A federal grand jury Thursday indicted disgraced former Assembly Speaker Sheldon Silver for allegedly lining his pockets with nearly $4 million in bribes and kickbacks in a stunning abuse of power dating to at least 2000, officials confirmed.

The Manhattan politician, acknowledged as the second-most powerful Democrat in the state, was charged in the three-count indictment with wire fraud, mail fraud and extortion.

Each charge carries 20 years behind bars.

Silver, 70, surrendered at FBI headquarters Jan. 22 and soon stepped down as Assembly speaker. He remains a member of the Assembly and has said he’s “confident” he will be “vindicated.”

His stunning arrest capped a secret grand jury probe that began in June 2013, court papers said, and marked the latest in a string of public corruption cases spearheaded by crusading Manhattan US Attorney Preet Bharara.

Silver’s lawyers, Joel Cohen and Steven Molo, issued a joint statement saying, “Our client is not guilty. We can now begin to fight for his total vindication. We will do our fighting where it should be done: in court.”

Sheldon Silver Indictment