The Honolulu Liquor Commission has opened another investigation into whether three watering holes at the Waikiki Trade Center should close earlier to reduce late-night problems.

The Shack Waikiki, Zanzabar and Black Diamond Nightclub, at 2255 Kuhio Ave., have cabaret licenses that allow them to stay open until 4 a.m.

Anna Hirai, acting administrator of the commission, said she will request at a hearing today that the commission force the bars to close by 2 a.m. to reduce police complaints, some of which include underage drinking.

Last summer, the bars faced a similar investigation following numerous assaults at the property. At the time, police told the commission that the trade center had the most assaults on the island.

In response, the bar owners and building management took measures to curb violence, such as staggering their closing times, hiring off-duty deputy sheriffs for security and roping off areas.

The commission decided the measures were adequate and dismissed the investigation.

But Hirai said there have since been “;developments,”; including more information from police, complaints from the public and liquor violations. She said more details would be released during today's hearing.

Michelle Yu, Honolulu Police Department spokeswoman, said complaints about the trade center are an “;ongoing issue,”; but she wasn't aware of recent problems at the property. The commander of the Waikiki District was not available to comment yesterday.

Louis Erteschik, vice chairman of the Waikiki Neighborhood Board, said the board hasn't discussed the issue for a while, adding, “;It may have gotten a little bit better.”;

Attorney Mark Kawata, who represents Black Diamond, said it was no surprise that the issue was revived because the commission had promised to review it. He said the complaints are probably against the other bars.

Kawata said the commission may require all the bars to be 21 and over, which wouldn't affect Black Diamond. However, he said, forcing the bars to close earlier would have a “;significant impact.”;

Management at The Shack Waikiki and Zanzabar could not be reached for comment.