Police media in Sydney said on Friday that detectives attached to the Northern Region Unsolved Homicide Team have re-opened the investigation into Mrs Winfield's "suspicious disappearance".
A mother of two, Mrs Winfield was reported missing in 1993 - 16 years ago this Wednesday - by her estranged husband.
A police spokesman said no new information had yet come to light, but detectives were now interviewing people in the local area.
Ms Winfield, who was 31 at the time of her disappearance, was last seen at her home in Sandstone Crescent on the night of May 16. An investigation by Ballina Police in 1998 led to a 2002 Coronial inquest that found Mrs Winfield was deceased.
However, despite the coroner's recommendation that "a known person" be charged with her death, the director of public prosecutions at the time said there was insufficient evidence to lay charges.