Federal agents on Thursday arrested powerful New York Assembly Speaker Sheldon Silver (D) on federal corruption charges, stemming from payments he received from two New York City law firms.

Jennifer Queliz, a spokeswoman for the U.S. Attorney’s office in the Southern District of New York, confirmed Silver was in custody Thursday morning. U.S. Attorney Preet Bharara held a press conference announcing the charges Thursday afternoon.

Silver is charged with five counts of fraud and conspiracy, according to court documents filed Wednesday. Prosecutors allege he used his position to take more than $6 million in bribes and kickbacks, which he masked as legitimate income earned as a lawyer over 15 years.

“Silver took advantage of the political pulpit to benefit from unlawful profits,” FBI Special Agent Richard Frankel said in a statement. “We hold our elected representatives to the highest standards and expect them to act in the best interest of their constituents. In good faith, we trust they will do so while defending the fundamental tenets of the legal system. But as we are reminded today, those who make the laws don’t have the right to break the laws.”

The documents allege Silver received $1.4 million in salary from the law firm of Weitz & Luxenberg based on his official position as assembly speaker, rather than for work he performed, and $3.9 million in attorney referral fees. Prosecutors say Silver steered $500,000 in state funds to an unnamed doctor for research; the doctor in turn steered asbestos cases to the firm.

The New York Times, which first reported the impending arrest on Wednesday evening, said Silver turned himself in to FBI agents in Lower Manhattan.

“I hope I’ll be vindicated,” Silver said Thursday as he arrived at FBI offices, according to the Times.

Silver, a Manhattan Democrat who has served as speaker of the state assembly since 1994, has been under federal investigation over payments he received from a small law firm, Goldberg & Iryami, that specializes in New York City real estate taxes. Investigators said Silver failed to disclose the payments on annual financial disclosure filings.

Silver also faces charges in connection with that case, although the firm isn’t named in charging documents. It is referred to as a “Real Estate Law Firm.”

Marcia Horowitz, a spokeswoman for Weitz & Luxenberg, said the complaint shows the firm was not involved in wrongdoing. “The Firm, which has fully cooperated with the Government in this matter, was not aware of any improprieties whatsoever,” Horowitz said in an e-mail.

Bharara said Silver’s alleged actions were indicative of a larger culture of corruption in Albany, where Silver has served since winning election in 1974.

“The show-me-the-money culture of Albany has been perpetuated and promoted at the very top of the political food chain. And as the charges also show, the greedy art of secret self-reward was practiced with particular cleverness and cynicism by the Speaker himself,” Bharara said. “Politicians are supposed to be on the people’s payroll, not on secret retainer to wealthy special interests they do favors for. These charges go to the very core of what ails Albany – a lack of transparency, lack of accountability, and lack of principle joined with an overabundance of greed, cronyism, and self-dealing.”

The Times reported the investigation grew out of Gov. Andrew Cuomo’s (D) decision to shut down an anti-corruption commission, known as the Moreland Commission, last March.

As assembly speaker, Silver is one of the three most powerful people in Albany. He was easily re-elected speaker by his colleagues earlier this month even after news of the FBI investigation broke.

New York state law requires anyone convicted of a felony to resign from office.