Nairobi - Two female Kenyan middle-distance runners have been dropped from the team for this month's IAAF World Championships in Doha due to high levels of testosterone, Athletics Kenya said on Friday.

Jackline Wambui, who won the 800m in Kenyan trials last week with a personal best time of 1:58.79, and Linda Kahega, who came third in the 400m, had both qualified for the world championships.

The two have fallen foul of rules which have led to a long stand-off between South African two-time Olympic 800m champion Caster Semenya and the International Association of Athletics Federations (IAAF).

Blood tests showed the two Kenyan runners had testosterone levels higher than allowed by the IAAF, said Paul Mutwii, Athletics Kenya's vice-president in charge of competitions.

"All the females athletes in the team (for Doha world championships) were subjected to the blood tests after the national trials in Nairobi on September 13, and the doctors found that both Wambui and Kageha had high levels of testosterone," Mutwii told AFP.

"As a result they cannot compete in Doha as the new IAAF decision rules out female athletes with high levels of testosterone from competing in events from 400m to the mile."

It is too late for the two athletes to be replaced, and Kenya will thus only be represented by only Hellen Syombua and Mary Moraa in the 400m and by Eunice Sum in the 800m.

In May, another two Kenyan athletes Maximilla Imali and Evangeline Makena were dropped from the team for the IAAF World Relays championship in Japan after blood tests showed high levels of testosterone.

The new IAAF rules came into force on May 8 and oblige women higher than normal male hormone levels - so-called "hyperandrogenic" athletes - to artificially lower their testosterone to run at some distances.

The most famous victim of the rule is Semenya, who is refusing to take the medication and will thus not take part in Doha.

The world championships run from September 27 to October 6.