The Australian Olympic Committee has agreed to reopen its case against swimmer Nick D'Arcy after the Court of Arbitration ruled it had not followed the correct procedures in banning him from this year's Olympics.

D'Arcy was kicked off the team last month when AOC President John Coates ruled that the swimmer had brought the sport into disrepute after he was charged over an alleged assault on former Commonwealth Games swimming champion Simon Cowley in March.

D'Arcy appealed to CAS which handed down its findings.

CAS agreed that D'Arcy's behaviour had brought the sport into disrepute but said Coates did not have the authority to exclude him from the team.

"Thus, at the relevant time (and still) it is the AOC which has the discretion, not the President of the AOC," the CAS statement read.

"It is quite clear that the decision to terminate was taken by Mr Coates personally in his role as President of the AOC and was communicated the appealant as such.

"This means that the proper procedure laid down by Clause 2 of the Membership Agreement was not followed."

The AOC released a statement saying it would reopen the case. A spokesman said the hearing was likely to take place within the next week.

"The matter will now be readmitted to the AOC for it to consider whether his membership of the team should be terminated or not," the AOC statement said.

"The AOC will consider the best way forward as soon as possible."

D'Arcy was thrown off the team because of his alleged involvement in a brawl at a Sydney nightclub that left Cowley with serious facial injuries including a broken jaw and nose, fractured eyesocket, crushed cheekbone and fractured palate.

D'Arcy had been out celebrating his inclusion in the Australian team for Beijing when a fight broke out.

He was charged by police and is due to face a Sydney court next month.

The AOC excluded him from the Olympic team after carrying out a separate investigation, which D'Arcy appealed against.

Reuters