Russian swimmer Vitaly Melnikov has been given an eight-year ban by the International Swimming Federation (FINA) Doping Panel after failing an out-of-competition drug test.
The 26-year-old tested positive for a growth hormone on March 29 and will now banned until April 21 in 2024.
Melnikov had previously served a two-year doping suspension from 2013 to 2015 after a positive test at the 2013 European Short Course Championships.
On that occasion, he was found to have taken the banned blood booster erythropoietin, leading to him being stripped of a 100 metres backstroke silver medal and a 4x50m medley relay gold from the Championships.
Melnikov is now set to be stripped of all results achieved on or after March 29, including having to forfeit any medals and prizes and reimburse any money won.
Melnikov had missed out on qualifying to represent Russia at the Olympic Games in Rio de Janeiro.
FINA have also announced that Bulgarian diver Bogomil Koynashki has been given a four-year ban after a failed test at their National Championships in July.
Koynashki tested positive for the banned substance Carboxy-THC, the active agent in cannabis.
His four-year period of ineligibility began on October 20.
The diver represented Bulgaria in three competitions at last year’s European Games in Baku but failed to earn a medal.