The segment was shown at show's Idol Gives Back charity special in which Brown even challenged other nations to match its commitment to purchase 20 million mosquito nets to help protection Africans from malaria.
The whole world requires 120 million nets that would cost $9.86 (five pound) each to protect the spread of the malaria virus carried by mosquitoes.
The British prime minister told viewers of the syndicated talent search, "I am proud to say that Britain is once again taking the lead... by supplying the funds for 20 million more bed nets. That's one in six of the 120 million bed nets the world needs."
He added, "I'm challenging the rest of the world - governments, business and anyone else who wants to end this killer disease - to join us in this effort by donating money for nets."
The Malaria No More campaign was behind the TV appearance of Brown, who is a fan of talent shows.
