The Civil Aviation Safety Authority has announced that a team of six experts will investigate Qantas's response to a string of recent emergencies, including an emergency landing at Manila after an exploding oxygen bottle blew a hole in the fuselage of a Boeing 747.

But Labor senator Kerry O'Brien said: "It is not good enough for the regulator to respond after the event. One would hope that they had been applying the same level of scrutiny, or something approaching it, in the lead-up to these events.

"CASA should be issuing Qantas with a 'please explain' about the matters which have come to public attention recently. It is nothing less than their job to inquire into public concerns about Qantas."

Senator O'Brien was a member of the Senate inquiry into CASA, which The Sun-Herald understands will deliver a critical report next week on the regulator's performance.

Last month's inquiry heard from several witnesses, including retired CASA inspector David Klein, that the regulator was too close to Qantas and relied on it to monitor its own overseas maintenance.

"Barely 20 per cent of the ports have been audited by CASA in the past five years and total faith has been placed in the Qantas internal audit system for regulatory compliance," he told the inquiry.

Yesterday Qantas confirmed it had decided against sending two 737 jets to Malaysia for major maintenance work following the recent incidents.

CASA has also announced that it is setting up a panel of experts to investigate toxic air in aircraft cabins. The Expert Panel on Aircraft Air Quality has been set up after The Sun-Herald revealed an engineer was overcome by toxic fumes on a Qantas flight from the US last year.

CASA spokesman Peter Gibson dismissed claims of close ties to Qantas: "I think the problem is that people say that but generally don't back it up with any evidence."