Digital currency exchange BTER announced that it has lost 7,170 bitcoins, or roughly $1.75 million at press time, in an apparent hack on its cold wallet system.

In a statement posted to the China-based exchange's website, the company said that it had shut down its platform in the wake of the attack and that withdrawals for user balances "will be arranged later".

A separate post on Chinese social media platform Weibo from BTER claimed that it was working with law enforcement officials on the matter.

Initially, BTER had posted on its website that a "security check" was underway and that the exchange would be temporarily suspended prior to another update. It remains unclear exactly how the BTER cold wallet was compromised.

BTER says it is offering a 720 BTC bounty "for chasing it back", although the company did not elaborate on the exact nature of the bounty. CoinDesk has reached out to BTER for comment on the hack but did not receive an immediate reply.

The stolen funds were broadcast through this transaction, according to the announcement, and the bitcoins appear to have been split into a number of separate wallets since the alleged intrusion.

The incident comes months after BTER suffered a hack on its servers, during which 50m NXT, worth roughly $1.65m at then-current prices, were stolen. At the time, the exchange was reportedly able to negotiate for a partial return of those funds.

CoinDesk will continue to monitor this developing story and post updates as they become available.

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