Police are also awaiting identification of further remains found on the banks of the River Dee in Chester on Friday.
The 37-year-old has now been missing from her home in Flintshire for over three weeks.
Catherine Gowing from Flintshire has been missing for three weeks. Human remains have now been found at a second location.
In an emotional press conference, the sister of Catherine Gowing, who has been missing from Flintshire since last Friday, appealed to the community for their help in finding the 37 year-old.
– Emma Gowing, Catherine's sister
Check your lanes, streets, car parks, garages and wasteland. Please look, please search, please help us find my beautiful sister.
Catherine is a kind, sensitive, beautiful person. She's passionate about animals and devoted to her family.
She's my best friend, the light of my life and the light of my parents life.
If you have any information however trivial please contact the police
Police are appealing for information to help them trace the plum/burgundy coloured Renault Clio belonging to Ms Gowing.
The last known sighting of the 37 year-old was at Asda in Queensferry, Flintshire.
She was seen entering the store at 8.06pm on Friday 12th October and she left at 8.39pm.
Police investigating the disappearance Catherine Gowing have been given more time to question a 46 year-old man on suspicion of her murder.
Further investigations by North Wales Police have established a further sighting of the 37 year-old at Asda in Queensferry, Flintshire.
Catherine was seen entering the store at 8.06pm on Friday 12th October and she left at 8.39pm.
She was wearing blue jeans, a light brown / khaki fleece zipped top with white sleeves and white side panels. On her feet she was wearing plain black flat shoes and her brown hair was tied up.
She had a bright brown saddle bag across her shoulder and body and was carrying a plastic Asda bag and a pizza type box.
Detective Superintendent John Hanson said: “Our priority is to trace Catherine and we would urge anyone who has seen her or her Renault Clio, bearing the Irish registration plates - 00D 99970 to contact the North Wales Police incident room on101.”
North Wales Police have issued a statement expressing their growing concern about the welfare of Catherine Gowing.
The 38 year-old has not been seen since leaving Evans Veterinary Practice in Clayton Road, Mold, where she works at around 7pm on Friday night.
Police were notified after Ms Gowing failed to make a weekend appointment and did not turn up for work on Monday morning.
They say this is totally out of character for Catherine who maintains regular contact with her family, friends and work colleagues.
The main focus of the investigation is now locating the missing 38 year-olds plum/burgundy coloured Renault Clio bearing Irish registration plates - 00D 99970.
North Wales Police strongly believe tracing the car will help to find Catherine.
A 46 year old Gwynedd man believed to be known to Catherine has been arrested on suspicion of her murder and is currently being questioned at a local Police Station.
Police investigating the disappearance of 38-year-old Catherine Gowing from the Flintshire area have arrested a man on suspicion of murder.
Ms Gowling was last seen by friends in Mold on Friday evening.
Detectives are also trying to trace her car which is a purple Renault Clio with an Irish registration plate.
Anyone with information is asked to contact police on 101 or Crimestoppers on 0800 500111.