SYDNEY, March 2 (Reuters) - Britain's air force chief says it was "unacceptable" its former pilots were being recruited to train Chinese military, and intelligence agencies in Australia and Britain had shared information to warn pilots against working for Beijing.

In October Britain said it would change the law to make it an offence for a former military pilot to continue training a foreign military after being warned by British intelligence agencies to stop.

The Royal Air Force's Air Chief Marshal Mike Wigston told the ABC in an interview at the Avalon Air Show in Australia the warnings were about China.

"We made the decision to go public on this in a very loud, clear way, that it's unacceptable and it's something that we were prepared to call China out publicly," he said.

Australia said it will also tighten the law to stop the practice. Australia's spy chief last week hit out in his annual security threat assessment at former military pilots who turn to working for authoritarian regimes, describing them as "lackeys, more 'top tools' than 'top guns'".

"Because of our close intelligence relationship with Australia and other allies, we all shared that information, we were all alert to it, and we have been in lock step with the Australian authorities throughout this process," Wigston told the ABC.

He said he believed the public warnings had worked.