Australian police are investigating an alleged sabotage of a Qantas plane, they said Wednesday, as the airline's chief was called to explain to parliament why he grounded the strike-hit carrier.
Qantas stranded tens of thousands of travellers around the world Saturday when chief executive Alan Joyce ordered the immediate shutdown of all flights to counter the threat of escalating industrial action from unions.
The alleged sabotage, which was reportedly related to an in-flight entertainment system, occurred before the grounding which Joyce said he was forced to call because strike action was bleeding the carrier.
Qantas refused to comment on the incident, but police said they were investigating.
"The Australian Federal Police (AFP) is aware of an alleged incident involving a Qantas aircraft which was undergoing maintenance at Brisbane Airport, that occurred on Wednesday 26 October," the force said in a statement.
"This matter is the subject of an AFP investigation," it said, adding that it would be inappropriate to comment further.
Steve Purvinas, from the union representing licensed aircraft engineers, said the incident related to the inflight entertainment system and posed no safety threat to passengers.
"From our perspective the most likely cause of this would be damage during manufacturing," he told public broadcaster ABC.
The Qantas shutdown, which came as Prime Minister Julia Gillard was hosting world leaders at a Commonwealth summit in Perth, ended after the government took the case to its industrial watchdog, which terminated the action.
The airline and unions now have 21 days to strike a deal over wages and conditions. The period could be extended by another 21 days, but if this process fails the watchdog can force a binding decision on both sides.
But the 46-hour grounding of Qantas' entire fleet, which ended Monday afternoon, has caused a political firestorm for Gillard over whether she could have acted sooner to avert or halt the unprecedented shutdown.
Qantas head Joyce, who has stridently defended his actions as necessary, is now set to be questioned by a senate parliamentary committee about what he told the government before the dramatic grounding of Qantas' entire fleet.
"The role of senate inquiries is to try and clear the air on matters like that," Greens leader Senator Bob Brown told ABC radio.
Joyce is due to appear before a Senate committee looking at amending two pieces of legislation relating to the airline, including the Qantas Sale Act which stipulates that the iconic carrier must remain 51 percent Australian owned