Melbourne wheel's safety investigated

One of the cabins on the Melbourne Star observation wheel has been taken out of commission while Victoria's workplace safety authority investigates complaints.

The inquiry was prompted by several complaints from passengers who have ridden the wheel since it reopened on December 23, News Corp Australia reports.

WorkSafe confirmed to News Corp an investigation was under way after concerns were raised by a passenger.

The new 120-metre high Melbourne Star observation wheel replaced the first wheel, which was shut down in January 2009 when a three-day heatwave caused the brace and supports to buckle and crack only a month after it opened.

Operators said an "early warning" alarm was triggered on two occasions since the wheel reopened but did not say what triggered the alarm or whether the incidents were connected.

"All cabins operate on individual systems, and standard operating procedure required that this cabin has been taken out of service whilst a full investigation is undertaken," the wheel's chief executive Chris Kelly told News Corp.

"This has no impact on the safe operation of the remaining 20 cabins at the Melbourne Star."