The newly disclosed documents stem from a separate case against Mr. Singh in the Eastern District of New York, where prosecutors there had charged him in September 2015 in a political corruption case in Nassau County.

Mr. Singh pleaded guilty in October 2016 to six counts stemming from bribery schemes involving local government officials on Long Island and several businesses he owned there.

He also pleaded guilty to conspiracy, bribery and honest services wire fraud, in connection with campaign contributions to Mr. de Blasio, according to the records. Those charges were not previously made public.

The federal information describes Mr. Singh’s negotiations with an unnamed New York City agency to renew a lease for one of his businesses. The details in the indictment match Mr. Singh’s efforts to renew a lease with the Department of Citywide Administrative Services for his Water’s Edge restaurant, which operated on city property in Queens.

Mr. Singh started raising campaign contributions for the unnamed official in 2010, ultimately raising tens of thousands of dollars, according to the records. Mr. Singh was one of the earliest large donors when Mr. de Blasio began his mayoral campaign in 2010, and he, his family members and other associates ultimately raised a total of about $33,000 for the mayor.

The information also refers to several actions by Mr. Singh and city officials that contributed to the conspiracy. It refers to an Oct. 12, 2013, fund-raiser that Mr. Singh hosted at his restaurant. On that date, campaign finance filings indicate, the de Blasio campaign held a fund-raising event at Water’s Edge.