The mother of a woman missing believed murdered broke down in tears at an emotional press conference today.

Qi Yu’s parents Zhihe and Qing He have flown in from China to assist with the investigation into their daughter’s disappearance and alleged murder.

As Detective Superintendent Kerry Lewis began to talk through the 28-year-old’s final movements, her mother sobbed and rocked in her chair, staring at a piece of paper clutched in her hands.

Zhihe and Qing He Yu address the media after arriving from China following the alleged murder of their daughter Qi, whose body is still missing. (AAP) (AAP)

It was a photo of her beloved daughter, which she held up to the camera.

28-year-old Qi Yu went missing on June 8. Police are focusing their investigating on bush land near Berowra, which the cadaver dogs have today been sent into. (AAP) (AAP)

Qi’s mother had given a small smile to waiting media as she took her seat. Her husband, who was wearing a jovial ‘Australia’ hat sat sombrely.

Chinese student Qi Yu was last seen at her share house in Campsie on June 8.

The 19-year-old man she rented a room to, Shou Dong, has been charged with murder.

19-year-old Shou Dong has been charged with murdering Qi Yu, but he isn't cooperating with police. (AAP) (AAP)

Since being taken into custody Dong has allegedly refused to assist authorities in finding Ms Yu’s body.

Mr Yu spoke to journalists today.

He said: “Our daughter has been missing for 18 days… both of us can’t sleep every night. My wife’s tears run dry.”

After outlining the last known whereabouts of his daughter’s car, found dumped in Burwood. Mr Yu concludes with a plea:

“If you have any information regarding my daughter and her whereabouts, please contact police at 1800 333 000. Thank you.”

On her husband’s final word, Mrs Yu begins to cry uncontrollably.

Mrs Yu sobbed and begged during a press conference with her husband, as they pleaded with the community for answers on their missing daughter Qi. (AAP) (AAP)

The pair desperately started handing out photos to the room, before being escorted away.

Det Supt Lewis says the couple are clutching to glimpses of optimism.

“They are obviously distraught… they still have some element of hope… but they’re also aware it’s been 18 days and the likelihood of finding their daughter alive is obviously non-existent.”

Mr and Mrs Yu desperately hand out pictures of their daughter to the media as they conclude their press conference. (9NEWS) (9NEWS)

Police believe Qi’s car is key to their investigation.

They have phone records that prove the student’s car visited bushland around Hornsby, Berowra, Cowan and Mt Kuring-gai from Campsie, on the night of her disappearance.

Any witnesses who might have seen the Toyota Corolla hatchback with green P-plates and number plate DLK-13P are being urged to come forward.

The search for Ms Yu’s body continues, with officers on foot, marine command and the mounted unit all scouring dense bushland in Berowra.

Today, cadaver dogs have been brought into the operation.