The advertising authority says controversial car rental company Wicked Campers has continuously failed to respond to complaints about its branding.

In a new decision, the Advertising Standards Authority has upheld another in a long series of complaints against the company which has drawn headlines and created outcry with its offensive branding.

The latest decision is the 20th case brought to the authority against the Wicked Campers since 2015 and the 16th that's been upheld.

The complainant in the case said the statement painted on the back of one of Wicked's vehicles is offensive and in poor taste and trivialises the rape of young boys.

The company did not reply to a request from the authority's Complaints Board for a response.

The authority has agreed the advertisement offends against generally prevailing community standards.

The Complaints Board noted this particular advertiser has continuously failed to respond to numerous complaints.