Crown Court judges also hear other cases passed on to them by the Magistrates Court.
Muliaina's manager Simon Porter did not respond to a request for comment.
The Rugby World Cup winner was arrested by UK police on April 4, shortly after his Irish club team Connacht lost 14-7 away to Gloucester at Kingsholm Stadium.
The alleged incident occurred in the first week of March, the same night Muliaina was out with teammates in the Welsh capital of Cardiff.
The group were out after Connacht's controversial 18-17 loss to the Cardiff Blues at Cardiff Arms Park on March 6.
Muliaina and others left an expat Kiwi bar for a nearby nightclub at 3am.
At the time of his arrest, Porter said the former All Black was "pretty upset" and "shocked" about the allegation.
Muliaina joined Connacht last year but has since signed with Italian club Zebre.
"I can confirm the club is monitoring the situation, also via the player's agent, and we're waiting for the decision," Leonardo Mussini, Zebre's media manager, told the Herald on Sunday this week.
"[Right] now Muliaina is confirmed as a Zebre Rugby 2015/16 player."