Matthew Newton caused uproar on a flight from Sydney to Melbourne earlier this week when he delayed take-off.

The Underbelly star, who is currently being investigated after his hotel room was trashed last weekend, was apparently heckled by his fellow passengers after throwing airline staff into a panic.

Newton reportedly boarded the already-delayed flight with lots of hand luggage, before exiting the aircraft again, leaving flight attendants to locate the stowed bags. He then re-embarked the plane, when staff had to start the packing process again.

One onlooker told The Daily Telegraph: "He sat in the first row next to the door while the hosties found room to put his four or five carry-on bags all the way down the aisle. Then he suddenly got up and walked off back up the air bridge and into the terminal."

They continued: "But they couldn't find the final one and by then people were yelling that he should be brought back on board to identify them himself. Then he walked back on and sat in his seat."

The source added: "It was a 3.45pm flight already delayed by lightning but because of Newton we didn't take off until 5pm. One passenger in particular was giving him heaps about it."