Passengers described fearing for their lives, but Malaysian Deputy Transport Minister Abdul Aziz Kaprawi said a Sri Lankan national, who appeared to have been drunk, was overpowered by passengers and crew and later arrested.
Kuala Lumpur-bound Flight MH128 departed Melbourne at 11:11pm (1311 GMT) on Wednesday but turned back shortly afterwards when a man allegedly threatened those on board, Australian police said.
His court appearance came as Victoria Police came under fire for its response time to the incident.
Ashton said the process took about 90 minutes and armed police then boarded the plane and arrested the suspect.
Passengers subdued him and tied him up with belts. "He was essentially trussed up as the flight returned to Melbourne".
Officers have confirmed that the man is believed to suffer from mental illness. He did not enter pleas to the charges. He did not ask for bail or enter a plea; his next court date is scheduled for August 24.
Scott Lodge said he was one of four passengers who "pounced" on Marks.
Ashton described the device the man carried as an "amplifier-type instrument". "It has cords that allow you to plug it into some sort of phone device to play music on", he said.
Sri Lankan man Manodh Marks, 25, who has been living in the Melbourne suburb of Dandenong on a student visa, is accused of threatening to blow up the plane.More news: Theresa May invokes post-Brexit trade with India to win votes
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Mr Leoncelli, a former professional Australian Rules football player, said it had two antennae and what appeared to be a smartphone input.
The plane returned to the airport about 30 minutes after takeoff.
Police wearing body armour removed the man off the plane.
The airline and authorities are investigating the incident, while Melbourne airport warns that there may be ongoing delays through the day as a result of the earlier shutdown. "Safety and security are of Malaysia Airlines' utmost priority".
When the man charged the aisle and tried to enter the plane's cockpit, passengers and crew aboard the flight stirred to action and were able to wrestle him to the ground. It is believed to have crashed in the southern Indian Ocean but no trace of the plane has been found.
The premier of the state of Victoria, Daniel Andrews, also commented on the incident, urging officials not to ban mentally ill passengers from flying.
"Then he started going louder: 'No I need to see the pilot.' And got louder and louder and eventually they screamed for help".
"However we'd like to land and have the device checked", the voice said.