BBC News with Jim Lee.

Researchers say a medicinal gel being tested in South Africa has almost

halve

d the risk of women being infected with HIV when

routinely

use before sex. The World Health Organization and the UN AIDS agency called the results

groundbreaking

. Here's Bethany Bell.

Researchers in South Africa say that a gel they've tested among 900 women cut the risk of HIV infection by 39%. Those who used the gel regularly had their risk of infection lowered by 44%. But the gel's effectiveness appear to

decline

after 18 months. The gel which contains an AIDS drug is still at an experimental stage.

An investigation by the Washington Post Newspaper says the intelligence and surveillance system created in the United States after the September the 11th attacks in 2001 has become so big that its effectiveness can no longer be determined.

Here's Kevin Connolly.

More than 250 government bodies have been created or reconstructed since 9.11, producing a system so complex and extensive that no one can be quite sure how much it costs or how effectively it works.

In all 2,000 private companies and nearly 1,300 government agencies were involved in counter-terrorism at 10,000 sites

scatter

ed across the United States.

The Obama administration has expressed fears that the article might help America's enemies locate its intelligence installations, but it hasn't answered the core charge of costly and uncontrollable inefficiency.