LONDON (AFP) - The sexual abuse of children in developing countries is increasingly being live-streamed on Internet services such as Skype, Britain's online child protection agency warned on Tuesday.

Paedophiles are increasingly targeting poor families abroad, exchanging access to live video images of children in exchange for payment, the Child Exploitation and Online Protection Centre (CEOP) said.

The agency said live-streaming emerged in 2012 as a means of producing and distributing indecent images.

"Offenders have been seen to target vulnerable families overseas to facilitate live access to children over webcam," the government agency said in a report.

"The children are made to engage in sexual activity in exchange for payment to the family or to an organised crime group." The agency said that of a sample of 146 victims identified in October 2012, 96 per cent were white, including those of Latin American or southern European appearance.

The other four per cent were of Asian appearance, the report said.

In its annual assessment of the threat of child sexual exploitation, CEOP also warned of a possible increase in abuse in Brazil as visitors head there for the 2014 football World Cup and 2016 Olympic Games.

The report said the number of images and videos shared online by British paedophiles in 2012 rose two-fold in a year to 70,000, although CEOP said this included a large number of duplicated images.

Around 50,000 British Internet users were involved in downloading and sharing indecent images in 2012, the agency estimated.