Police are yet to charge any suspects with the murder of Sarbjit Kaur more than two months after she was found unconscious in her Wolverhampton home.
But West Midlands Police believes a woman seen near the two-storey gated property may have crucial information needed to track down the killer.
The force has now released digitally enhanced images from CCTV footage captured on the day the 38-year-old was murdered in Goldthorn Hill.
WATCH: Police make fresh appeal in Sarbjit Kaur murder investigation. Video by Juliet Hounam
Detective Inspector Jim Munro, of force CID, said: "We believe this female may hold some vital information in relation to Sarbjit's murder.
"She was in and around the area of Rookery Lane on the morning of February 16.
"We want this person to either come forward or for some people to provide us with information as to who she may well be."
The woman seen in the CCTV is about 5ft 2ins, wearing a dark-coloured fur-lined hooded coat and dark bottoms, and is carrying a large Sports Direct bag.
Do you recognise this woman? Take a look at the CCTV images
Officers have visited about 500 properties across the city since Mrs Kaur's death, with residents completing a questionnaire about what they may have seen on the day of the murder.
But police are keeping an 'open-mind' about whether Ms Kaur knew her attacker, Det Insp Munro said.
He added: "We remain open-minded in regards to the events. We know that Sarbjit was strangled, she died of asphyxiation, so therefore our inquiry has been very focused around house-to-house and CCTV enquiries.
"We are making progress in relation to the events of that day but I would urge the public to assist us where they can."
Mrs Kaur was discovered by her husband just after 4pm as he and his children returned to their detached Rookery Lane home - opposite the street’s junction with Tudor Crescent.
Two men, aged 42 and 32, were arrested and remain on police bail, while a 39-year-old woman was released with no further action.
The family continue to be supported by specially trained officers, the officer said.
Det Insp Munro, who has been with the force for the past 18 years, added: "Sarbjit's family are obviously still very distressed around her death as they continue to come to terms with what's happened."
Detective Chief Inspector Chris Mallet from the force’s homicide team added: “This is an extensive and painstaking murder enquiry.
"Mrs Kaur’s family are devastated by her death and are still trying to come to terms with their loss; they need answers."
Anyone with information should call DCI Chris Mallet or his team on 101.