SEC Chair Gary Gensler, who is in the midst of a hefty crackdown on crypto companies, offered to serve as an advisor to Binance’s parent company in 2019, according to the lawyers for Binance and founder Changpeng Zhao.

Documents filed by the SEC on Wednesday indicate that attorneys from Gibson Dunn and Latham & Watkins, one of Binance’s law firms, allege that Gensler offered to serve as an advisor to the crypto exchange in several March 2019 conversations with Binance executives and Zhao. He eventually met Zhao in Japan for lunch later that month, the filing claims.

At the time, Gensler was teaching at Massachusetts Institute of Technology’s Sloan School of Management. He was appointed head of the SEC in 2021 by President Biden, and over the past year has come down hard on the crypto industry, suing numerous companies for allegedly selling unregistered securities.

Earlier this week, the SEC filed 13 charges against Binance and Zhao, alleging the company failed to register as an exchange and broker-dealer, improperly commingled funds and lacked critical internal controls over its businesses.

Before Gensler started going after Binance, he was trying to cozy up to the company, the lawyers say. The Wall Street Journal previously reported on Gensler and Binance’s relationship, citing internal Binance messages and a person close to the SEC chair. Both suggested that Binance approached Gensler.

In the latest filing, the Gibson and Latham attorneys say that Zhao continued to stay in touch with Gensler after the March meeting. And at the future SEC chair’s request, Zhao sat down for an interview with Gensler as part of a cryptocurrency course he was teaching at MIT.

The SEC on Tuesday described Zhao, who reportedly resides in the UAE, as a “foreign national” with a tendency for “geographic elusiveness.” Zhao’s lawyers now say that the Zhao understood that Gensler was “comfortable serving as an informal advisor.”

Later in 2019, the letter said, Gensler was slated to testify before the House Financial Services Committee, and he sent Zhao a copy of his intended testimony ahead of the hearing.

In July of that year, Gensler testified before the House over Facebook’s proposed and later canceled cryptocurrency Libra and its planned Calibra wallet.

“I do not advise any financial, technology, blockchain or other companies, nor do I own any cryptocurrencies,” Gensler’s prepared testimony read.

Gensler’s advice to lawmakers at the time was largely the same as his public statements today. He said that, with Facebook envisioning a wallet to store customer assets, rules needed to be in place “to guard against Calibra’s use or potential abuse of such customer funds.”

He also testified more broadly in language that’s resembles his latest pronouncements.

“We must guard against illicit activities, such as tax evasion, money laundering, terrorist financing and avoiding sanctions,” he said at the time. “We must protect individuals’ privacy.”

Because of Gensler’s ties to Zhao, Binance’s lawyers said they’d asked for his recusal from any actions regarding the company. They say they got no acknowledgement from SEC staff.

An SEC spokesperson said in a statement to CNBC that, “the Chair is very familiar with and full compliance with his ethical obligations including any recusal obligations.”

The SEC’s probes into Binance.US and Binance began in 2020 and 2021, respectively, well after Gensler and Zhao’s last alleged contact.

WATCH: SEC wages war against crypto industry