Malawi police have arrested two women in their mid-20s after they used kwacha bank notes as decorations for a cake they had baked and posted it on social media.

A police spokesman said the pair had posted the image of the cake festooned with 70 to 500-kwacha notes – worth $35 (£28) on social media as they advertised their cake-making business.

The accused have not commented on their arrest but police say they will be charged with an offence of “damaging and unlawful use of currency”.

In the past, Malawi’s central bank has said it incurs huge costs printing new banknotes to replace worn-out ones and blamed improper use of banknotes as one of the reasons the notes have to be regularly replaced.

The offence of “damaging and unlawful use of currency” carries a large maximum fine.