A stamp mistakenly featuring the image of a Statue of Liberty replica rather than Lady Liberty herself will cost the US Postal Service a whopping $3.5million.

The US Postal service was sued by Las Vegas sculptor Robert Davidson who created the famed replica of the Statue of Liberty that resides in the New York-New York casino-resort in the buzzing Las Vegas Strip.

The mailing service used the replica's face in its 2011 'Forever' stamp design, launching the copyright infringement lawsuit.

The US Postal Service has been ordered to pay Las Vegas sculptor Robert Davidson $3.5million after they printed stamps with his Lady Liberty sculpture's face on it in 2011

Spot the difference? The US Postal Service printed stamps using Davidson's design (right) instead of the original (left)

Attorneys argued in court filings that Davidson's replica was unmistakably different from the original and was more 'fresh-faced', 'sultry' and even 'sexier'.

The Postal Service released the stamps September 14, 2011 and sold them for at least three months before they realized the image was not of the original statue.

Attorneys for the Postal Service said the design was too similar for Davidson to claim copyright.

However last week Federal Judge Eric Eric Bruggink sided with Davidson and agreed his work was an original design with a more modern, feminine and contemporary face.

He ordered the Postal Service to pay $3.5million to the artist - a slice of the $70million the service made in profit from the stamp.

Davidson's sculpture pictured above in front of the New York-New York hotel and casino on the Las Vegas Strip

Postal Service spokesman Dave Partenheimer said the agency would make a comment 'if and when appropriate.'

Todd Bice, Davidson's attorney, said in an emailed statement that his client was pleased that the court recognized the significance of his work.

'As the court noted, Mr. Davidson's artistic creation of the Las Vegas Lady Liberty is highly unique and attractive, which is what prompted the US Postal Service to select a photo of his work for the second ever Forever Stamp, over hundreds of other images,' he said.

Court documents show Davidson said he wanted his sculpture, like the rest of the casino-resort's facade, to have the feel of New York's iconic skyline without duplicating it.