American heiress Paris Hilton is threatening legal action against a Wellington company which used her picture on a billboard with the word "vacant" written across it.

Media5 used the photo, which showed Hilton partying, to advertise vacant billboard space.

Hilton's manager Jamie Freed said from Los Angeles Media5 had not gained permission to use the image and could expect to hear from her lawyers.

Media5's Adam McGregor said the company was just having a "bit of fun" with the billboard, which was designed to draw attention to unsold display.

A friend had come up with the concept of using high-profile public figures, Mr McGregor told the Sunday Star Times.

"We were thinking about using Winston Peters, but Paris is much prettier and she has a proven ability to laugh at herself.

"We assume that the agency has taken care of the rights to the image of Paris, but we will ask the question."

The company would remove the image if Hilton's lawyers requested that, Mr McGregor said.

"We're not trying to offend anyone."