Police are continuing the hunt for the killer of a young pregnant woman at Logan, south of Brisbane.

The body of Joan Canino Ryther, 27, was found in the front yard of a Woodridge home on Wednesday morning.

Detective Superintendent Dave Hutchinson says she was bashed with a blunt object and raped.

He says investigators want to hear from a man heard crying outside a house in Mayes Avenue on Tuesday night where the victim lived.

"This is a person who was allegedly around the premises of 95 Mayes Avenue around about 8:30pm - a male in a yellow top that night that was heard sobbing," he said.

He says officers also want to hear from some people seen drinking at a rotunda in Mayes Park on the night in question.

"Anybody who was congregating around that rotunda on that Tuesday evening - we would like them to come forward also," he said.

He says police have no firm suspects.

"We currently would have up to 40 investigators and intelligence officers and that is in addition to all the forensic police and the uniform police that are out searching the area, so we have a very large taskforce working on the job," he said.