Securency, which is a joint venture between the Reserve Bank of Australia (RBA) and Cumbria-based packaging film manufacturer Innovia Films, is currently being investigated by the Serious Fraud Office (SFO) and the Australian Federal Police (AFP).

The investigation, which centres around the alleged payment of kickbacks to foreign government officials by overseas agents of Securency, has led to five UK arrests following a coordinated operation by 80 members of the SFO, supported by officers of Surrey, Hampshire, Thames Valley, Cumbria and the Metropolitan police services.

Meanwhile, the AFP has raided six residential properties in Australia, while two search warrants have been executed in Spain by Spanish authorities in relation to three British nationals.

SFO director Richard Alderman said: "This is an excellent example of how anti-fraud agencies around the world are working together to fight economic crime. It requires much painstaking preparation to co-ordinate action like this and I am delighted that our collective hard work has resulted in successful searches in a number of jurisdictions."

Both the RBA and private equity firm Candover, which owns Innovia Films, are understood to be pursuing a sale of their 50% stakes in the £108m-turnover company while, according to reports in the Daily Mail, Candover is also planning to sell Innovia Films next year for up to £600m.

Securency pioneered the production of polymer banknotes, which are popular in hot, humid countries where paper degrades quicker, with the launch of its Guardian substrate.