Eight days after a runner spotted 33-year-old Zhuojun "Sally" Li's remains wrapped in plastic in bushes on December 9, police returned to Sir Joseph Banks Park near Sydney Airport on Tuesday, and discovered a second person's body.
While yet to be identified, it is likely her missing husband Jai-Bao "Rex" Chen, Detective Superintendent Danny Doherty told reporters.
"There's a fair degree of decomposition ... after being where it's been since probably late November," he said.
The second body was found within about 10 metres of the first, Det Supt Doherty said.
"But it's completely covered over, and had been submerged in very thick bulrush reed and other foliage, it makes it nearly impossible to see."
A second body found near Zhuojun 'Sally' Li is likely her husband Jai-Bao 'Rex' Chen, police say. (HANDOUT/NSW POLICE)
A silver Toyota Avensis had earlier been seized in Sydney and was being forensically tested as part of the investigation.
CCTV captured the vehicle stopping on the northern side of Foreshore Rd in Botany, near the park, between 4am and 5am on November 30.
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.
Police are working on a theory the pair were killed at their suburban Greenacre home in Sydney's west, potentially over debts, and the car used to transport their bodies.
"We are treating it as, more than likely, a targeted double murder," Det Supt Doherty said.
Investigators want dashcam video from anyone driving near Sir Joseph Banks Park at the time. (Mick Tsikas/AAP PHOTOS)
Those responsible may have then travelled to Queensland - where Mr 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," Det Supt Doherty said.
Ms Li had been reported missing early in December after her mother was unable to contact her.
Investigators have contacted Mr 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," Det Supt Doherty said.