Police are hunting the driver of an Audi A3 convertible after a mother was killed in a suspected hit-and-run.
Erika Prisacaru, 39, died in hospital after being struck by a car on The Grove, Dorchester, Dorset, shortly before 20:00 GMT on 27 December.
Dorset Police has already appealed for any mechanics asked to fix a damaged car in the days after her death to come forward.
It has now released CCTV images of the vehicle believed to be involved.
Three men arrested after the crash have been released without charge.
Insp Joe Pardey said: "Following detailed inquiries we believe we have identified a vehicle that was in The Grove at the time of the collision.
"This is a dark-coloured convertible Audi A3 and may have been driven by a black man."
He said the car was "noticeably dirty".
Investigations showed the vehicle left Station Road in Brewery Square at about 19:40, was in The Grove at the time of the collision and returned to the Brewery Square area at about 19:55, he added.
Police previously said they also urgently wanted the drivers of four cars seen in the area at the time of the crash to come forward.
The victim's six-year-old son Andrei is being looked after by relatives, officers said.
"A little boy has been left without a mother as a result of this collision and I would again appeal directly to the driver to please do the right thing and come forward," Insp Pardey said.
"It is imperative we speak to you to establish what happened that night."
A statement, released by police on behalf of Ms Prisacaru's family, described her as a "much-loved" daughter and "loving" mother.
"Words cannot described how we feel. Our lives are destroyed and we feel empty without hope," the family said.