Police are investigating a hack on a Christchurch-based cryptocurrency exchange.

Cryptopia employees are currently speaking to police after experiencing what the firm is calling a "security breach".

The hack has resulted in "significant losses" and trading has been suspended while police investigate.

The exchange had been experiencing "unscheduled maintenance" since January 13.

Cryptopia was founded more than three years ago by Rob (Hex) Dawson and Adam Clark.

It allows users to trade a range of cryptocurrencies including Bitcoin, Litecoin and Doge. It has 1.4 million users.

Cryptocurrency news site Coindesk reports the hack resulted in the loss of 19,391 Ethereum (ETH) tokens worth $2.44 million and 48 million Centrality (CENNZ) tokens worth $1.18 million.

The missing tokens were all reportedly transferred from Cryptopia to unknown wallets.

A statement from police confirmed a significant value of cryptocurrency may be involved in the alleged hack.

A dedicated team is being set up in Christchurch to establish what happened and police will be liaising with relevant partner agencies in New Zealand and overseas.

Cryptocurrencies have collapsed in value over the past year since reaching all time highs at the end of 2017.

Newshub.