United States athlete Gil Roberts has been handed an eight-year suspension after testing positive for banned substances for a second time.

An out-of-competition test taken by Roberts in September detected multiple banned substances including ostarine, which boosts muscle growth.

In 2022, Roberts, 35, was given a 16-month ban after testing positive for ostarine and andarine.

He avoided suspension in 2017 after he was found to have ingested probenecid – a banned diuretic and masking agent – by kissing his girlfriend, who was taking medication containing the drug for a sinus infection.

The US Anti-Doping Agency’s chief executive officer Travis Tygart said it was important to “apply the full force of the rules”.

“All athletes deserve a level playing field so that their hard work and talent are rewarded,” Tygart said.

Roberts was a member of the United States’ gold medal-winning 4x400m relay team at the Rio 2016 Olympics.