Badminton Asia Technical Committee chairman Chih Shen Chen has apologised to two-time Olympic medallist PV Sindhu for the "human error" committed by the referee during the women's singles semifinal match of the Badminton Asia Championships in April.

Sindhu had been left in tears after an "unfair" call by the umpires midway through her semifinal match against Japan's Akane Yamaguchi saw her go down in three games and eventually sign off with a bronze medal, her second in the continental championship.