UK-based Blue Star invested £50,000 in payments firm Sthaler in return for 1.45% of share capital.Early stage identity and payments firm Sthaler created technology which let a consumer identify themselves and pay using just their finger, Blue Star said in an announcement.The technology was called 'Fingopay' and is widely adopted in Japan, the investment firm said.Blue Star said in a statement the deal allowed it to invest an additional £300,000.The terms of further investment need to be agreed with Sthaler.Blue Star chairman Graham Parr said the firm believed Sthaler had the potential to play an important part in the payments world."We look forward to working with Sthaler's management to maximise its potential," Parr said.Shares in Blue Star were up 7.69% to 0.350p on Monday at 08:17.