Internet search company Google signed an agreement with Brazilian public prosecutors on Wednesday to help combat child pornography on its social networking site Orkut, an accord that the company believes is the first of its kind internationally.

Under the agreement, Google will use filters to remove and prevent illegal content on Orkut, which has about half its users in Brazil. The company will also facilitate evidence gathering under judicial order in suspected crimes against children and teen-agers on Orkut without the need for international legal accords.

Google will also preserve for six months access logs of users being investigated for illegal conduct.