Bahrain 400m runner will keep her world title from 2019 but will miss the Tokyo Olympics.

Salwa Eid Naser will miss the Olympic Games this summer after the Court of Arbitration for Sport upheld an appeal by World Athletics against a ruling by the federation’s own disciplinary tribunal which had cleared Nigerian-born Naser of missing doping tests.

The 23-year-old ran 48.14 for 400m to win the world title in Doha in 2019 – a time that only world record-holder Marita Koch and Jarmila Kratochvilova from the 1980s have beaten.

Naser was provisionally suspended last year after breaking rules relating to her availability to undergo anti-doping testing. But the Athletics Integrity Unit [AIU] disciplinary tribunal ruled in October that Naser had not violated anti-doping rules.

However CAS has now overturned that decision and ruled that the two-year ban should begin immediately.

The Nigerian-born sprinter will however keep her world title from 2019.