FTX sues crypto exchange Binance and its former CEO Zhao for $1.8 billion

The estate of collapsed crypto exchange FTX has filed a suit against Binance and its former CEO Changpeng Zhao in an effort to wrest back at least $1.76 billion, citing a "fraudulent" share deal.

In a Sunday filing with a Delaware court, FTX cites a 2021 transaction in which Binance, Zhao and others exited their investment in FTX, selling a 20% stake in the platform and a 18.4% stake in its U.S.-based entity West Realm Shires back to the company.

The FTX estate alleges that the share repurchase was funded by FTX's Alameda Research division through a combination of the company's and Binance's exchange tokens, as well as Binance's dollar-pegged stablecoin.

"Alameda was insolvent at the time of the share repurchase and could not afford to fund the transaction," the suit claims, labeling the deal agreed with FTX co-founder Sam Bankman-Fried — who's now serving a 25-year sentence over fraud linked to the downfall of his exchange — as a "constructive fraudulent transfer."

CNBC has reached out to Binance for comment.

The litigation marks the latest escalation of tensions between two of the biggest names in crypto, after the meteoric collapse of FTX rocked the market.

This breaking news story is being updated.