Sydney police say a husband and wife whose bodies were discovered in bushland may have been killed over unpaid debts, before the killers fled overseas.

The badly decomposed remains of Jai-Bao ‘Rex’ Chen were found on Tuesday at Sir Joseph Banks Park near Sydney Airport.

His well-hidden corpse was just metres from where a jogger stumbled upon Chen’s wife’s body in bushes eight days earlier.

Zhuojun ‘Sally’ Li’s corpse was found wrapped in plastic on December 9.

The 33-year-old had been reported missing earlier this month when her mother was unable to reach her.

Chen’s body was found within 10 metres of the first, but was “nearly impossible to see’, Detective Superintendent Danny Doherty said.

It was “completely covered over, and had been submerged in very thick bulrush reed and other foliage,” he said.

While yet to be identified, Doherty said it was likely Li’s missing husband.

“There’s a fair degree of decomposition … after being where it’s been since probably late November,” he said.

An international manhunt has been launched as police work on a theory that Li and Chen were killed over “financial debts”.

Police believe there may have been two killers. Detectives are working with authorities in China and Taiwan to track them down.

“We are treating it as, more than likely, a targeted double murder,” Doherty said.

It’s believed the double murder may have happened at the couple’s suburban Greenacre home in Sydney’s west.

A car was then used to transport the bodies to the airport.

A silver Toyota Avensis had earlier been seized in Sydney and is being forensically tested as part of the investigation.

CCTV captured the vehicle stopping on the northern side of Foreshore Road in Botany, near the park, between 4-5am on November 30.

Police set up a crime scene in bushland near Sydney’s airport. Photo: AAP

Investigators appealed for dashcam footage or information about the car or its drivers, including from trucks and tradespeople who might have driven past at the time.

Those responsible may have then travelled to Queensland — where Chen’s phone was recovered — before travelling overseas.

“We now have made a number of liaisons with Taiwan authorities and Chinese authorities … We believe there’s at least two people involved, and both have travelled overseas,” Doherty said.

Investigators have contacted Chen’s family in Taiwan.

“They’re obviously in shock, they’re processing the fact that we’ve just found a body, possibly of their loved one,” Doherty said.

-with AAP