A Dunedin man is accused of remotely erasing evidence from his cellphone while police investigated him for child sex offending.

Thirty year old Nicholas Birch is on trial before the Dunedin District Court on charges of performing an indecent act on a person under 16 and attempting to pervert the course of justice.

Crown prosecutor Robin Bates told the jury the defendant contacted the complainant through Facebook when the boy was 15.

Birch allegedly offered the teenager $500 to indecently touch himself and that figure later rose to $1500.

Robin Bates says Birch also asked the boy to send a photo of his genitalia via Snapchat, which the teen did.