LAUSANNE, Switzerland — Jamaican sprinter Nesta Carter has testified at the Court of Arbitration for Sport to appeal against disqualification from the 2008 Olympics in a doping case that cost Usain Bolt a 4×100-meter relay gold medal.

Carter shielded his face from media on arriving at sport’s highest court on Wednesday for a closed-doors hearing that ended around seven hours later.

The court said lawyers for Carter and the International Olympic Committee would submit further documents to the judging panel, which was expected to reach a verdict early in 2018.

The 32-year-old Carter is challenging his disqualification imposed by the IOC for a positive test for a banned stimulant.

Carter tested positive for methylhexaneamine last year in a reanalysis program of samples from the 2008 Beijing Olympics and 2012 London Olympics.

The case spoiled Bolt’s perfect Olympic record of three gold medals — in the 100, 200 and 4×100 — at three consecutive games from 2008-2016.

Carter and Bolt were teammates on the relay team in Beijing, which won in a world record of 37.10 seconds. Carter ran the opening leg, and Bolt took the baton third in a team that also included Michael Frater and Asafa Powell.

Carter also teamed with Bolt on three straight world championship relay-winning teams, from 2011 through 2015. They were also teammates when Jamaica set another 4×100 world record in 2012 at the Olympics, running 36.84.

Dozens of athletes tested positive for banned drugs in an IOC-ordered reanalysis program using new and more accurate tests on samples stored since the 2008 Beijing Olympics and 2012 London Olympics.

The majority of more than 110 cases involved steroids and athletes from the former Soviet republics. Carter’s case was the only one involving Jamaica.