The advertising watchdog has told the makers of Shark drink to withdraw a poster showing male and female models covered with scratches, bruises and bite marks.
Twelve members of the public contacted the Advertising Standards Authority (ASA) to complain that the four posters were offensive.
The first poster shows a naked man lying on his front and four deep scratch marks across his back.
In the second the face of naked woman is angled towards the camera, revealing a red bruise on her neck.
The third and fourth posters have a number of similar photographs.
All four have the words "Shark victim" and "bring out the beast".
'Sharking' connotations
The drink's maker Shark AG, told the ASA it used the idea of a shark attack "because it combined a humorous reference to the product and a light-hearted word play on the colloquial term "sharking" - or the search for a partner.
They say they sought advice from the body set up to help advertisers on what might breach industry rules before going ahead with the posters.
But on Wednesday the ASA ruled in its adjudication that it "nevertheless considered the posters were sexually explicit" and it said that they "could be seen to condone sexual violence".