Burundian athlete Francine Niyonsaba returns home after breaking the world 2000m record in Zagreb last week, clocking 5:21.56 secs, just days after she won the 5000m in Zurich in 14:28.98. The former Olympic and world 800m silver medallist, like South African Caster Semenya, has fallen foul of World Athletics regulations that prohibit athletes who have unusually high levels of testosterone from competing in races between 400m and a mile unless they undergo treatment to reduce the levels. IMAGES AND SOUNDBITES