Weitz & Luxenberg hired legal ethics expert Roy Simon to conduct an independent review of its payments to former Assembly Speaker Sheldon Silver, and Simon said he found the firm did nothing wrong.

In a criminal complaint against Silver, the Southern District U.S. Attorney’s office last month claimed Weitz & Luxenberg paid Silver more than $3.2 million from 2003 through November 2014 for referring asbestos cases. Prosecutors said Silver did no work on the cases and used his official position to direct $500,000 in state funds to support research by the doctor who referred clients to the firm. The firm faces no charges.