Caspian is a documentary project shot in the sanatorium town of Naftalan, where people "gather to bathe in chocolate-brown oil, purported to have therapeutic properties," says the Panos Pictures photographer. "It was startling to see a substance normally associated with industry, politics, power and wealth, being used for health and relaxation. This ‘miracle oil' has been bathed in for centuries."

This particular point particularly impressed Victoria Forrest of Design by Victoria Forrest, one of the judges in BJP's IPA. "I like the fact that this series is so poignant in terms of world events, and yet it shows a tradition that has been going on for centuries."

For Alexia Singh, the editor-in-charge, wider image desk at ThomsonReuters, it was the images' real art sensibility, combined "with a good understanding of geopolitical issues," that warranted Mathews' win. "Every single frame is really strong," she says. "It will look stunning in a gallery."

Dewe Mathews wins a one-week exhibition at the Host Gallery in London from 22 November. She will also see her images printed by Spectrum Photographic, one of Europe's leading fine art pro labs. Finally, she will receive a Nikon D700 digital SLR with a 50mm f/1.4G lens, worth more than £2600.

"I'm extremely happy," Dewe Mathews tells BJP. "I just came back from New York, and I haven't slept all night, so I'm still unsure if all of this is true. But I'm really excited. I shot this project for that very purpose: to be shown, beautifully, in a gallery space, so I'm excited by this opportunity."

"The whole project has a real lightness of touch," says Karen McQuaid, a curator at The Photographers' Gallery, and the IPA's third judge after Charlotte Cotton of the National Media Museum was unable to attend today's judging session. "I can just hear the girls chattering while coming down the hill," she adds, mentioning one of Mathews' images [shown above].

Dewe Mathews' win comes two days after Facundo Arrizabalaga won the single image prize in BJP's IPA. His image of student protests shot in November 2010 will also be shown at the Host Gallery from 22 November.

For more on Chloe Dewe Mathews' win, read BJP's November issue out on 02 November, or visit www.chloedewemathews.com.