Handout of Sindri Thor Stefansson's pictureImage copyright Iceland police
Image caption Sindri Thor Stefansson was arrested in February

A man suspected of masterminding the theft of 600 computers that were being used to attack virtual currencies has escaped custody in Iceland, police say.

Sindri Thor Stefansson escaped the low-security prison through a window and fled to Sweden on a passenger plane that was also carrying Iceland's prime minister, local media report.

He used another man's passport but was identified through surveillance video.

The stolen computers, which are still missing, are worth $2m (£1.45m).

Mr Stefansson was among 11 people arrested in February suspected of involvement in the case, dubbed by local media as the "Big Bitcoin Heist".

The computers were stolen during four raids on data centres around Iceland, a popular location for such centres because almost 100% of the power generated there comes from renewable sources.

Ten days before his escape he had been transferred to Sogn open prison in rural southern Iceland, some 95km (59 miles) from Keflavik's international airport.

The prison is unfenced and inmates have access to phones and the internet, local news website Visir reports (in Icelandic). Sindri Thor Stefansson was not considered a dangerous inmate.

Details are still unclear but the suspect reportedly escaped early on Tuesday and guards reported him missing only after the flight had already left Keflavik for Arlanda airport north of the Swedish capital, Stockholm.

Iceland's Prime Minister Katrin Jakobsdottir was on her way to Sweden to take part in a meeting between five Nordic prime ministers and India's prime minister Narendra Modi. She has not commented on the escape.

An international warrant has been issued for Mr Stefansson's arrest.