Martelli played international rugby for the British Isles team on its 1899 tour of Australia.
He was described by British Isles tour manager, Matthew Mullineux, as having 'an excellent drop, punt and place kick'.
[3] There is some evidence that Martelli was not actually a Trinity player as recorded in most books and may have actually played for Dublin Wanderers.
Despite the confusion of his club background, he is known to have toured with the British Isles and played in 12 of the 21 arranged matches.
The game ended in a 13–3 victory for the Australians, and Martelli was replaced for the final three Tests by Charles Thompson.