Australian flag carrier Qantas launched an investigation Wednesday into claims it purchased headphones made in a Chinese jail where inmates who miss production targets are reportedly beaten and held in solitary confinement.

The Australian Financial Review said other big companies also allegedly used products made at Dongguan prison in the southern province of Guangdong, including British Airways and Emirates.

Two inmates recently released from the jail, including New Zealander Danny Cancian, told the newspaper they made disposable economy-class earphones for all three airlines.

Cancian, who was serving a four-year jail sentence for manslaughter, said failure to meet production targets meant prisoners were "taken outside and tasered".

"It's a very cruel environment. You wake up every morning wondering if you are going to survive the day," he said.

Another inmate, who asked not to be named, said he made inductors used in electrical appliances as well as the headphones.

"Yes, I made them for the Australian airline Qantas, the one with the kangaroo as its logo," he said. "We also made them for Emirates, British Airways and lots of others."

Cancian claimed prisoners were paid eight yuan (US$1.30) a month, and worked more than 70 hours a week.

"If they want to call me a liar then they should go there and have a look," said Cancian, adding that the headphones were placed in boxes with the company's names on them.

The report cited a representative from the Dongguan City Joystar Electronic Company as saying his firm used prison labour for big orders and made 300,000 sets of headphones for Qantas early last year. They were allegedly made to fill an order for Airphonics, the Vietnamese company Qantas confirmed was its main supplier.

Qantas said it had been unable to substantiate the allegations but had suspended arrangements with Airphonics and launched an investigation.

"Qantas is very concerned by allegations in today's media and we have immediately suspended our current sourcing arrangements until we can investigate more fully," it said in a statement.

It added that the claim its supplier used a third-party company in China to help fill orders "contradicts the verbal and written assurances we've had from this supplier that their supply chain process met our standards - including the ethical treatment of workers".

"Qantas places very strict conditions on suppliers and we conduct regular audits of factories ourselves to ensure those conditions - which include no forced labour - are met."

British Airways could not be reached for comment but the newspaper cited a spokesman as saying its suppliers "are subject to a rigorous procurement process prior to appointment".

"We enforce compliance to a robust labour-standards policy throughout the duration of the contract."

Emirates said it was satisfied there was "no evidence of any unethical practices in the headset manufacturing process".