Thank you Tina. I can supply a little more information.
Two days before capturing the animal photographed I caught a male Clepsis consimilana so my first thought was that this specimen, although much darker in colour and I think a little smaller in size, could be a female of the same species. I have found numerous photographs on the internet of both female and male Clepsis consimilana and none have markings at all like this one.
This led me to think that this is probably of a different species.