A second race horse owned by the...

A second race horse owned by the Aga Khan, the world’s most successful breeder, has failed a drug test in London and faces disqualification, officials said.

The 3-year-old filly Rifada, trained by Fulke Johnson Houghton, had traces of the illegal substance Naproxen in its system after winning the Warwick Oaks on June 24 and faces disqualification.

The filly Aliysa, who won the Oaks at Epsom two weeks earlier, faces disqualification after traces of camphor were found.