New banknotes issued by the Bank of Namibia in 2012 were found to be "ageing faster than expected" last year – prompting the central bank to make "technical improvements" and re-issue them.

The Bank of Namibia issued a new series of banknotes, with new security features. However the lowest denomination notes – N$10 and N$20 – began ageing just one year after they were issued.

Moreover, one of the main security features, a diamond shape containing optical variation ink, was beginning to fragment