A police spokesman said detectives had cleared the man seen cycling near Woodridge train station around the time the body of Megan Kirley, 40, was discovered at a semi-rural property at Karawatha on February 9.

"Police made an appeal for public assistance yesterday while releasing CCTV of the man riding a bicycle on Railway Parade," he said.

"Investigators have since spoken with the man and finalised the line of inquiry.

"However, we are still appealing for any drivers who were on Wembley Road between 2.45am and 3.20am on that day to come forward."

As part of the ongoing investigation, detectives were continuing to review all available CCTV footage and attempting to identify any people or vehicles seen in the area.

The spokesman said the major investigation was very much "active" but could not reveal what detectives were focusing their efforts on.

Ms Kirley suffered a single gunshot wound to her head and was found by the man she lived at the home with, 37-year-old Pieter Pickering.

He was believed to have been in a relationship with the victim for the past six months, who was staying with him at the time of her death.

Mr Pickering was questioned by detectives last weekend but released without charge.

On Friday, detectives spent almost four hours at the Karawatha property on Wembley Road shooting various guns and conducting tests on the sounds they made.

SES volunteers had also spent all week searching for evidence and examining the scene in bushland on the property.

Anyone with information should contact Crime Stoppers on 1800 333 000 or Policelink on 131 444.