The Skattestyrelsen, Denmark’s tax agency, is reportedly looking into 2,700 bitcoin traders who reportedly owe the government taxes for gains made trading the flagship cryptocurrency between 2015 and 2017.

According to a recently published press release, the Skattestyrelsen claims an unnamed Finnish cryptocurrency exchange was where the traders operated. In total, it claims, they bought and sold around $8 million worth of BTC, but failed to declare their earnings.

As such, the agency is going after these individuals. Kevin Bergen, te Skattestyrelsen’s tax director, was quoted as saying:

Right now we are identifying the individual citizens and keeping the new information up to those we already have. If something does not match, we will contact them and ask for more information. However, how many people it is and what it may mean, it is still too early to say.

It’s currently unclear which cryptocurrency exchange was involved, although Finland – which tipped off the tax agency – is known as the home for the well-known peer-to-peer bitcoin exchange LocalBitcoins. Interestingly, the exchange has earlier this year added anti-money laundering (AML) and know your customer (KYC) checks for some of its traders.

Bergen added that he believes this is “probably the tip of the iceberg,” implying the tax agency may in the near future go after other traders. Per his words, as it gains more knowledge “about data mining, segments and methods in general” it will become “wiser in the area” to better control transactions.

Notably, Denmark has earlier this month seen 1,500 restaurants restart accepting bitcoin payments through popular online food portal The portal had been accepting BTC payments for “quite some time” before, but removed the feature last year when the cryptocurrency was struggling with transaction fees and confirmation times.