Channel Seven reported last night that a woman has made an allegation against the Power midfielder.
While Koch said that allegation was being investigated, Powell-Pepper could face sanctions for breaching club rules in any case.
The club issued a statement late on Monday, confirming an investigation is underway.
“Port Adelaide are investigating an allegation one of their players was involved in an incident at an Adelaide bar on Sunday morning,” they said.
“The club has advised the AFL and will not be making further comment until it has all the information at hand.”
SA Police said on Monday night they had not received any complaint related to the alleged incident.
Koch told FIVEaa today that the allegations against Powell-Pepper were being investigated by the club.
“We want to get all the facts,” he said. “The only fact that we do know, which is really disappointing and something the leadership group will be looking into, is the fact that he was out after curfew at a nightclub… He broke that and that will be up for the leadership group to decide any sanctions.
“That is disappointing, but on an incident with another customer, we’re actually having to investigate that further and we’re doing that with the person involved and also the club and witnesses around it. We should be able to firm that up later today.”
Port recruited Powell-Pepper as a first-round selection in the 2016 national draft and he had an immediate impact last season, finishing third in the Rising Star award.
He has played 25 senior games and was in the senior team that beat Brisbane by five points on Saturday at Adelaide Oval.
– with AAP
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