Child sex tourism thrives in Kenya's port city Mombasa (2015) | 7.30

As many as one in 10 children are thought to be involved in the sex trade in Mombasa, Kenya, where sex tourists are fuelling a crisis. And a warning: This story contains sexual references.

Read more here: http://ab.co/1FDyLRm

Paul Adhoch heads the United Nations aid agency Trace Kenya, which battles the trafficking of children.

He believes sex tourists in Kenya are creating a crisis.

"They are not relaxing at some beach or enjoying the wildlife," Mr Adhoch told the ABC's 7.30 program.

"They are, specifically, deep in the communities, in poverty stricken areas looking for sex — nothing else."

The port city of Mombasa has been a centre of trade for hundreds of years and is now a hotspot for underage prostitution.

Trace Kenya estimates there could be as many as 40,000 child sex workers in the city, and the trade extends up and down the coast to the seaside resort towns of Malindi and Diani.

For more from ABC News, click here: https://ab.co/2kxYCZY
You can watch more ABC News content on iview: https://ab.co/2mge4KH

Subscribe to us on YouTube: http://ab.co/1svxLVE
Go deeper on our ABC News In-depth channel: https://ab.co/2lNeBn2
You can also like us on Facebook: http://facebook.com/abcnews.au
Or follow us on Instagram: http://instagram.com/abcnews_au
Or even on Twitter: http://twitter.com/abcnews