Caster Semenya to focus just on 800m after ditching 400m event

South Africa's Caster Semenya has decided against competing in the 400m at Rio 2016 to focus solely on the 800m.

The 25-year-old is the favourite to come out on top in the 800m event after remaining unbeaten this season and posting a leading time of 1:53.33 at the Diamond League meeting in Monaco.

Semenya, the subject of gender testing following her world gold success in 2009, was also tipped to take part in the 400m but has now ditched the race.

Margaret Wambui of Kenya and Burundi's Francine Niyonsaba are the second and third favourites for the 800m respectively.