Renowned documentary photographer Sebastião Salgado is to auction his limited-edition ?solid titanium? Leica M7 to raise money for the Brazilian rainforest.

One of a limited edition of just 50, the kit is expected to fetch up to ?70,000 (more than £47,000) when it goes under the hammer in Vienna, Austria on 27 November. The camera bears the special serial number 3,000,000.

The cash raised will be used to replant tens of thousands of trees in the Brazilian rainforest ? with every Euro funding the planting of two trees, according to auctioneers Westlicht Photographica.

Salgado ? who has twice won Leica?s prestigious Oskar-Barnack Award – has set up a trust for the protection of tropical rainforests.

The rare rangefinder camera was given to the Brazilian-born photographer earlier this year as a tribute to his humanitarian services as an ambassador for United Nations agency UNESCO.

It is part of a special series to mark last year?s 50th anniversary of the Leica M system – each engraved with the years from 1954 to 2004.

The auction house confirmed that the camera will be among around 800 lots for sale at its auction taking place at 11am on 27 November. In the past bidding has been possible from the UK, either online or by phone (for details see www.westlicht-auction.com)

Also up for grabs at the same auction will be a Leica R6 which Salgado used to capture photos of the first Gulf War, along with a number of original photos.

Picture credit: Westlicht Photographica Auction