Four rare battle flags captured during the American War of Independence by a British officer have been returned after more than two centuries to be auctioned.

The regimental colours seized in 1779 and 1780 by Lt Col Banastre Tarleton, who remains one of the conflict's most controversial figures, have already aroused huge interest among American military historians. They are expected to fetch between pounds 2.3 million and pounds 5.8 million at Sotheby's in New York next year.

Until recently the flags had hung in the Hampshire home of Capt Christopher Tarleton Fagan, the great-great-great-great nephew of the lieutenant colonel.

Capt Tarleton Fagan, a former Grenadier Guards officer, said: "I am very sad to sell them. They are an important part of our family history and we have had them for 225 years. However, there comes a time when their value is such that one can no longer afford to insure them.''

Only about 30 American revolutionary battle flags have survived, all of which, apart from the ones to be sold at Sotheby's, are in museums and in most cases only fragments remain. The ones captured by Tarleton are in excellent condition and their history is well documented. One is the flag of the 2nd Regiment of Continental Light Dragoons, raised in Connecticut by Col Elisha Sheldon, who were defeated by Tarleton in Westchester County, New York in July 1779. The other three flags were seized the following year in a still controversial battle in the southern United States. Tarleton crushed a Virginian regiment under Col Abraham Buford at Waxsaws near the border of North and South Carolina. Accounts of what happened next differ. According to the Americans, Tarleton ordered his men to slaughter more than 100 revolutionary soldiers who had already surrendered. But the British officer maintained that his horse was shot after a truce was declared and pinned him to the ground.