JMW Turner's Heidelberg with a Rainbow, an important watercolour in his oeuvre, is to appear at Sotheby's Important Old Master Paintings and Sculpture auction on January 31 in New York.

Heidelberg with a Rainbow has been previously owned by some of the most important collectors of Turner's work

The piece is expected to sell for $4m-6m. It was previously sold by Sotheby's in 2001 for £2m ($3.2m), which at the time was the record price for a Turner watercolour on paper. It was also the first time a Turner watercolour made more than $1m at auction.

Turner's Modern Rome - Campo Vaccino currently holds the title as the most valuable example of his work ever sold at auction, after bringing £29.7m ($47.8m) to a London auction in 2010.

Heidelberg with a Rainbow was commissioned from Turner in 1840 by engraver Thomas Prior. It is considered one of the most accomplished examples of his mature style, and has been housed in the collections of some of the most important collectors of his work, including that of Joseph Gillot and Sir Donald Currie.

Also featuring in the auction is a previously unknown panel from Hans Memling, which will sell with a $1.5m estimate.  

Spurred by the sale of John Constable's The Lock, which set a new record for the artist and now stands as the world's fourth most valuable old masters work after selling for £22.4 ($36m) in July, the old master art sector has experienced a 5.4% increase in value as of October 2012, according to the Mei Moses Art Index.

Sotheby's auction comes as part of New York's Old Master Week, which will see auctions from all of the top houses. You can find more on the most exciting consignments so far in our art & photography news section.