The chief executive of a cryptocurrency mining startup has reportedly disappeared with $35 million in client investments, Newsweek reported Monday.

Le Minh Tam, head of Vietnam-based Sky Mining, has been missing since July 26, according to the report. The startup, which claimed it would rent crypto miners to investors for between $100 and $5,000, received funds from roughly 5,000 individuals prior to Tam’s disappearance last week. Each miner would promise a 300 percent return over a year, with investors keeping the machines for at least 15 and up to as many as 18 months.

However, when one group of investors went to pick up their miners last Friday, they found that the firm’s mining facility and office were empty, and that the mining machines had already been taken away. Tam later reportedly claimed he sold them to cover financial losses, and that his disappearance was aimed at protecting his life.

He sent a similar message on Sunday, claiming that he would return, but Sky Mining deputy chairman Le Minh Hieu claimed the CEO had stolen the funds and relocated to the U.S.

Some investors have already filed lawsuits against the firm, though it is unclear if they will receive their funds back.

Vietnamese news outlet VnExpress reported that Tam controlled every aspect of the company, overseeing all mining operations and controlling all the funds.

Hieu said he tried to set up a temporary board to run the company in Tam’s absence, but death threats against him and his family forced him to shut it down.

Thief image via Shutterstock