A Harley-Davidson motorcycle signed by Pope Emeritus Benedict XVI is coming to auction at Bonhams Paris next year.

The FLSTC 103 Heritage Softail Classic has a $31,290 high estimate. It is one of two signed by the former Pope, who stepped down from the role in January 2013.

Pope Benedict signed the fuel tank before Harley-Davidson assembled the rest of the machine

Pope Benedict signed the fuel tank before the machine was built.

The other bike resides at the Harley-Davidson museum in Milwaukee.

Proceeds from the sale will benefit the Friendly World Association, a Polish charity that supports children and families.

In February, a Harley-Davidson signed by Pope Francis sold for $325,904. The discrepancy in price between that sale and the estimate of the Benedict-signed machine reveals the greater affection felt for the present pontiff.

However, hopes are high that the fact Pope Francis personally received the motorcycle from Harley-Davidson as part of the manufacturer's 110th anniversary in 2013 will boost its value.

"We hope to raise some spirited bidding for the very worthy charity selected," commented Ben Walker, international director at the auction house's motorcycle department.

"In February 2014, Bonhams sold 1,585cc Harley-Davidson Dyna Super Glide signed by His Holiness Pope Francis. Now we're delighted to offer a motorcycle received by both Pope Francis and Pope Emeritus Benedict XVI; it was present during a pivotal period in the papacy of the Catholic Church, and we expect a lot of interest in it."

The lot will be included in the Les Grandes Marques du Monde sale at Paris' Grand Palais on February 5.

We will bring you all the key results from the sale so make sure to bookmark the Paul Fraser Collectibles webpage.