Former BitMEX CEO Alexander Hoeptner has sued the cryptocurrency derivatives platform for $3.4 million for breach of contract and wrongful termination, a court filing shows.

Hoeptner joined the Seychelles-registered exchange in January 2021 at a time when top officers at HDR Global Trading Limited, the owner and operator of BitMEX, were embroiled in a lawsuit that accused the founders of facilitating unregistered trading.

It was previously reported that Hoeptner left the company in October 2022, without further details. Hoeptner now claims that he received a letter of termination citing misuse of funds and failure to perform duties, among other things.

"Such termination is wholly wrongful and without basis," the court filing said.

According to Hoeptner, BitMEX owes him a total of $3.4 million, including $2.4 million for his second-year bonus and smaller amounts for remaining wages, relocation expenses and housing, the court filing shows.

"At the direction of the founders and the board, I put my personal and family lives on hold in order to be on the ground managing operations in Singapore and Hong Kong," Hoeptner told CoinDesk. "I"m disappointed that it has gotten to the point that legal proceedings are necessary, but I"ve been left with no choice."

Hoeptner relocated several times during his time as the CEO of BitMEX, filings show, and split his time among Hong Kong, Germany and Singapore.

"There were no objections and/or concerns raised as to the Claimant's relocation and/or the costs that was to be incurred by the HDR Group in respect of the same," the filing says.

But sometime in July 2022 to August 2022, he was informed by the company that there was a possibility he wouldn"t receive his second-year bonus or any reimbursement for his relocation, citing "extensive cost-cutting and restructuring program which involved numerous layoffs."

His relocation expenditures at that point had amounted to $230,000, according to the filing. A few weeks later, he received a termination letter.

"We had made tremendous progress " hitting every milestone we set out " which made my wrongful termination even harder to understand," he said.

A BitMEX spokesperson told CoinDesk the exchange is unable to make any substantive comments at this stage as the matter is pending before the Singapore Court but that it will respond to Hoeptner's claims. "Needless to say, we will defend the claim vigorously," the spokesperson said.

The crypto exchange recently cut its workforce by 30% as it tries to pivot back to its initial focus on derivatives trading. Earlier this year, BitMEX's former CEO, Arthur Hayes, was sentenced to two years of probation after pleading guilty to charges of willfully failing to implement an anti-money laundering (AML) program at the exchange.

UPDATE (Dec. 19, 10:49 UTC): Added a comment from a BitMEX spokesperson.