London's transport authority has refused to display a poster featuring the 16th-century "Venus" by German artist Lucas Cranach the Elder, saying it is overtly sexual.
The painting, which depicts a golden-haired, milky-skinned woman cocking her hips behind a transparent veil, is one of 70 works due to go on display at London's Royal Academy of Arts on March 8.
Transport for London, which runs the British capital's subway system, refused to display a poster of the work unless the bottom half was cropped out, the academy said.
"I think it is because she's totally nude as opposed to say she's topless," academy spokeswoman Jennifer Francis said, noting the painting was completed in 1532. "We're shocked. We wouldn't have put a poster design forward if we thought it was offensive."
She said "Venus" was chosen because it best represents Cranach's work, and the academy would be uncomfortable altering the artist's work by cropping it.
Transport for London said they turned the poster down out of respect for commuters' varied tastes.
"We have to take account of the full range of travelers and endeavor not to cause offense in the advertising we display," the organization said in a statement.
It said its rules bar advertisements that portray people "in a sexual manner" or "in an overtly sexual context."
Cranach, a friend of Protestant Reformation leader Martin Luther, often painted nudes, Francis said. She added the academy saw nothing overtly sexual in the piece.
"We actually thought it was quite an innocent painting," she said.