Several investors in a Dutch ‘bitcoin factory for private individuals’ are considering legal action after the company, Koinz Trading, failed to come up with proper profits.

The Volkskrant said on Wednesday that several customers are demanding the computers which they have funded to mine for bitcoins back. ‘No-one knows where they are and some clients wonder if they actually exist?,’ lawyer Marco Kalmijn told the paper.

Kalmijn says investors have so far put around several million euros into the company, which is based in Lelystad.

The company is currently promising 0.2 bitcoin in payouts every month, for an initial investment of €6,100 for the computer. However, some customers say they have had no money since September, broadcaster NOS reported.

Koinz Trading was unavailable for comment on Wednesday but the owner told the Volkskrant earlier that the location of the factory must remain a secret because of the security issues. He also told the paper that payments are now being resumed.

Bitcoin has soared in value over the past year, from some €1,000 a year ago to over €10,000 today.