NEW DELHI - Auction house Bonhams will put under the hammer a rare Rolls Royce Phantom modified for tiger hunting by an Indian maharaja during the days of the British Raj, featuring a mounted machine gun and a cannon, that may fetch up to $1 million.

The custom-made 1925 Rolls Royce was originally commissioned by Umed Singh II, the maharaja of Kotah in the 1920s at a time when tiger hunting was hugely popular in India.

The flaming red vehicle, with a convertible canvas roof and bespoke hunting features including a double-barrelled shotgun, spotlights for night hunting and a mountable Lantaka cannon, is expected to fetch up to $1 million when it goes on the block in mid-August in Carmel, California.

"It was quite common, most of the maharajahs had specialised customised cars manufactured in the U.S. and they even had gilted frames and all sorts of things," said Pran Nevile, a writer and expert on India's colonial era known as the British Raj.

The car's 8.0-litre, 6-cylinder engine with a low gearing ratio allowed "it to creep powerfully through the roughshod jungles of Rajasthan", wrote Bonhams.

For centuries, big game hunting of tigers, leopards and Asiatic lions in India's forests was a favoured pastime of India's rulers from the Mughal emperors to the British elite.

While much tiger hunting was carried out on elephant-back, some Indian maharajahs, or "great kings" of princely states across India including arid Rajasthan, took things to the extreme.

"It was more for a show but everything would be ready and then they would then go and take this Rolls Royce up to a point or the hills and from there shoot the tiger that was already captured by their servants," Nevile told Reuters.

Indiscriminate hunting, however, decimated India's Bengal tiger population from an estimated 40,000 a century ago to about 1,700 today. Tigers are now a protected keystone species throughout Asia from Indonesia's Sumatra to Indochina and India.

Indian maharajas were known for their high living and extravagant spending on all manner of trappings including ornate palaces, vintage cars and Louis Vuitton bags.

The nawab, or ruler, of southern Hyderabad state used the famed Koh-i-Noor diamond, once the largest known gemstone in the world, as a paperweight, while the nawab of tiny western Junagadh state was renowned for spending lavishly on his dog's wedding. ?

"They wanted to live in ostentatious style. Being a princely lot they had their own grand style and it was even copied by the British," said Nevile.