Demand in India for the OnePlus One, the smartphone made by Chinese upstart OnePlus, has skyrocketed.

The device, which is sold exclusively through the company’s sales partner Amazon India, is being resold at as much as an 85 per cent premium on websites such as eBay, Olx and Quikr, the Economic Times said.

Not only are the handsets selling at a huge premium, the free invites to buy the device, which also are available only through its exclusive partner, are being sold for INR500-1,000 ($8-16) on Quikr.

The 5.5-inch device, with 3GB of RAM and 64GB of internal memory, was launched two weeks ago in India and retails for INR21,999 ($350). But, the Times said, the smartphone was listed at as high as INR40,800 on eBay India. Other sites have it selling at a 10 per cent premium.

One-year-old OnePlus has kept supplies limited, which has built-up its exclusivity and boosted demand.

To buy the handset, consumers first need to create a OnePlus account on Amazon, which will send them a free invite to make a purchase online within three days. Each buyer is given three invites to pass on to others within three days. Presumably, these invites are being sold.

OnePlus general manager for India, Vikas Agarwal, told the Times that demand was outstripping supply even as the company has been increasing production to meet demand. “As the demand-supply gap improves, we will explore introducing a pre-order system to reach out to a wider set of users,” he said.