A freelance photographer who began her career at the Croydon Advertiser has won a humanitarian photojournalism award.

Hazel Thompson collected the prestigious prize from charity CARE International at the Perpignan photojournalism festival in France, for her report on children in prison in the Philippines.

She gained exclusive access to Filipino jails after posing as an aid worker and witnessed the tragic state in which thousands of illegally detained children are confined in adult prisons, enduring abuse.

The harrowing photographs featured in her report Kids Behind Bars, and were chosen to receive the CARE award, which recognises the work of photographers who raise awareness about hidden or forgotten problems around the world.

Hazel, (27), trained at the Advertiser nine years ago before going freelance, and now has her own studio in Crystal Palace.

She said: "My passion is for photographing stories I believe in, pictures I know will make a difference.

"It's not just about the stories – although the impact of getting powerful photographs published is important. It is about giving a voice to the unheard, communicating through images to show people the truth and then giving them a chance to respond.

"I've worked with charities on a range of stories from rape survivors in South Africa to teenagers who are socially excluded in Romania because they have HIV."

Geoffrey Dennis, chief executive of CARE International UK, said: "CARE works with some of the poorest and most marginalised people in 70 countries around the world.

"We know that photography plays such an important role in bringing the realities of the developing world to a wide audience and can really inspire people to do something."