LOS ANGELES (AP) — Federal authorities announced new charges and additional defendants Monday in a wide-ranging corruption case against a Los Angeles city councilman and his alleged associates.

The new defendants include a former deputy mayor, the billionaire chairman of a Chinese real estate company and a Bel Air developer, according to a superseding federal indictment unsealed Monday in the Central District of California. The case is the first time federal prosecutors have levied charges under the Racketeer Influenced and Corrupt Organizations (RICO) Act in a public corruption investigation that ensnared a Los Angeles elected official.

The city councilman, Jose Huizar, was arrested in June on allegations he masterminded a $1.5 million pay-to-play scheme tied to the approval of large building projects. Prosecutors say the scheme sought to illegally profit from development of the city’s burgeoning downtown district.

The new indictment adds more charges in the case. Huizar left office earlier this year and previously pleaded not guilty. He is expected to be arraigned on the superseding indictment on Dec. 7. His attorneys did not immediately respond to a request for comment.

Nick Hanna, U.S. attorney in Los Angeles, called the scope of the alleged corruption “staggering” and said in a news release that Huizar and his associates "repeatedly violated the public trust by soliciting and accepting numerous cash bribes and other financial benefits, turning Huizar’s City Council seat into a money-making criminal enterprise."

The case has already resulted in guilty pleas from former City Councilman Mitchell Englander, a former Huizar aide, a City Hall lobbyist and two real estate consultants.

The “Operation Casino Loyale” investigation dates back to 2015, when authorities in Las Vegas noticed Huizar cashing out a large amount of casino chips from a billionaire Chinese developer, identified in Monday's court documents as Wei Huang, 55, a resident of Shenzhen, China. Huizar’s former aide acknowledged in his plea agreement that the scheme dates to 2013. Authorities have stressed that the investigation is not over.

Huang also has a home in San Marino, California, and is chairman and president of U.S.-based Shen Zhen New World I, LLC. He faces charges of bribery, honest services fraud and Travel Act violations. His company is also named as a defendant in the case.

Authorities say Huang sought to build a 77-story tower in Huizar’s district that would become the largest skyscraper west of the Mississippi River. The developer, who already had a hotel in the district, is accused of providing benefits worth $800,000 to Huizar and others that included a dozen trips to Las Vegas casinos and funds to settle a sexual harassment lawsuit against the councilman.

Huang and his counsel have been notified there is a federal warrant for his arrest. His attorney could not immediately be reached for comment.

Monday's superseding indictment also charges Raymond Chan, a deputy mayor who oversaw economic development for Los Angeles Mayor Eric Garcetti in 2016 and 2017. Also known as She Wah Kwong, he was additionally a former general manager of the Los Angeles Department of Building and Safety.

The allegations against Chan include agreeing to accept more than $100,000 for official acts to benefit a project by another Chinese developer.

Chan retired in 2017 amid praise from Garcetti calling him a “true public servant” whose “leadership has contributed to unprecedented growth across Los Angeles,” according to a city announcement.

Chan has been directed to surrender to federal authorities and is expected to be arraigned on the superseding indictment Tuesday.

His attorney, Harland Braun, said his client will plead not guilty and intends to fight the charges.

“He just did his job,” Braun said Monday. “He was shocked, I was shocked. He said ‘I’m not guilty of anything here. I want to testify, I want my trial.’ ”