A woman has been arrested in connection with the murder of a university graduate whose body was found in a burning car.
Catherine Wells-Burr, 23, was discovered in her red Ford Focus, which was abandoned in a field by the side of a road near Ilminster, Somerset.
A 32-year-old woman was arrested last night on suspicion of murder and currently remains in police custody.
Two men also arrested have been eliminated from the inquiry, Avon and Somerset Police said.
Detective Chief Inspector Simon Crisp said: "A post-mortem will begin today to try and identify how Catherine died.
"We still need information from members of the public and those people who knew Catherine or knew of her.
"It is imperative we get a full picture of her life and you may have information that could help."
Firefighters were alerted to the blazing five-door vehicle shortly before 6.30am on Wednesday off the A358 in Ashill.
Fire crews extinguished the flames and discovered the body of the Bath Spa University graduate inside the wreckage.
Avon and Somerset detectives have earlier confirmed they are treating her "tragic and brutal" death as suspicious.
On August 25 Miss Wells-Burr updated the cover photo on her Facebook profile with a picture of a woman covering her face with a book.
Accompanying the picture was the cryptic message: "You can't start the next chapter of your life if you keep re-reading the last one."
Detective chief inspector Simon Crisp, who is leading the investigation, said yesterday: "This is a tragic and brutal incident in which a young woman has needlessly lost her life.
"We are working to establish what happened in the early hours of yesterday morning that led to this car being set ablaze.
"I am making a double appeal today. Firstly for those people that may have witnessed Catherine and her red Ford Focus arriving at the scene which is alongside the A358 near Ilminster.
"Did anybody see that car arrive? Did anybody see suspicious people arrive or leave the scene at about 6am to 6.30am on a busy road? We need you to call us.
"The second part of the appeal is to help us understand Catherine's private and social life.
"Did she know her killer is the question that we're asking ourselves. Did she arrange to meet somebody at the location where she met her death? These are the things we are seriously considering.
"Please don't leave it to others to tell us, call us immediately.
"The post-mortem examination is yet to take place so I am unable to confirm whether she died in the fire or beforehand.
"I believe we are still searching for the offenders. At this moment there is not a specific person we are looking for.
"There are many lines of inquiry that we are examining; one of those is that this may not have been a random attack and that Catherine knew her killers or killer.
"I can assure you we will find those responsible and bring them to justice."
Tributes were paid to Miss Wells-Burr, who lived in the town of Chard with her family and achieved a first-class degree in business management.
Maurice Hicks, head teacher of Holyrood Academy in Chard where she was a former pupil, spoke of his shock at the news.
"Everyone at Holyrood Academy is deeply saddened and shocked to hear the news about Catherine," he said.
"She is warmly remembered as a very friendly young person, gregarious and with a great sense of humour.
"Catherine always had a smile and a positive outlook. She was very popular with the other students and had lots of friends.
"Our sincere condolences go to her family and friends at this difficult time."
Friends also took to social networking sites to pay tribute to Miss Wells-Burr.
Polly Derbyshire left a message on the Facebook page R.I.P Catherine Wells-Burr (official).
She said: "R.I.P Catherine. I'll remember you as bright, beautiful, funny and hardworking. My deepest Sympathy to all of her family."
Joss George added: "Although I hardly knew you, I remember you when you were a little girl playing in the garden next door to us. You were such a lovely little girl, singing and dancing. Such a happy child. Life can be so cruel. You will be missed very much."
Timmy Jay, using the name Timmybadger, tweeted: "Really shocked and saddened to hear of the tragic death of Catherine Wells-Burr. Caf was a beautiful, sweet person."
Miss Wells-Burr worked as a business analyst for Chard-based Numatic International Ltd, which is best known for manufacturing Henry vacuum cleaners.
The firm was directing all inquiries to Avon and Somerset Police.