Detectives are examining a kitchen knife found close to where a pretty young teacher was hacked to death on a new housing estate.

And family and friends shocked by the slaying have paid tribute to the much loved young mum who was found bleeding to death on Friday night.

Staff and pupils at Hetton School returned to lessons today to learn 28-year-old Andrea Howarth had been murdered.

Her former boss at Hetton School's IT department Howard Brown described his devastation at his colleague and friend's death.

Mr Brown brought the 28-year-old back to Hetton School, where she first taught as a student four years ago, from Castle View School in Sunderland, and helped the young mum move house to Wingate on Thursday, during half-term, as she waited for her new home there to be built.

He said: "She was excited, over the moon about it all.

"Her sister and brother-in-law were putting the plumbing in; everything was happening for her. She had a new house, a new start and a new job in our school. Everything was on the up for Andrea. That was the last time I talked to her.

"I can't believe it, it's devastating."

Andrea, whose maiden name was Metcalfe, went to Wellfield Comprehensive School in Wingate, then East Durham College in Peterlee, before enrolling on a teaching course at Sunderland University.

Mr Brown first met her when she came to the North Road school on teaching practice.

She landed her first job as an IT teacher at Castle View School in Hylton Castle, teaching there for two years, before returning to Hetton last September.

Mr Brown said: "Andrea was young, bubbly, fresh, full of ideas and full of life.

"She was frail - she had been diagnosed with MS during the summer holidays - but never let it get her down.

"The students loved her. She ran a Monday lunchtime computer group and had other clubs running every day. She was a fantastic teacher who put everything into it.

"It's going to be a very, strange day. I just can't believe this has happened."

Hetton headteacher Richard Horn said tearful staff and pupils were being told of her death at special meetings throughout the day.

"Many will already know, but we are taking steps to hold special meetings with tutor groups and staff.

"She was a very good, very effective teacher and a valuable member of staff. She was very brave after her diagnosis with MS.

"Andrea had only been with us for a term-and-a-half, but during that time she showed herself to be a friendly, pleasant and cheerful person. The news has come as a big shock. She will be badly missed by everybody."

He added: "Her family and close friends will be suffering very much and all our thoughts and sympathies are with them, at this very difficult time."

Members of Andrea's family said she would be missed by everyone who knew her.

In a statement issued on behalf of her sisters Elaine Ramsey and Julie Briggs, and the whole family, her brother Billy Metcalfe said: "Andrea was the gentlest, most loving person you could wish to know. She had a wide circle of friends who will miss her. Her life centred around her son, Callum, her home life and her profession as a school teacher.

"Andrea was an outgoing person, whose openness and honesty left no-one in any doubt of her feelings and opinions. She was a fun-loving person and always made the room come to light whenever she entered.

"There will be a space in everyone's life who knew and loved her."

The mum-of-one had just moved to a new housing estate in Wingate, County Durham, and was making her way home from her local pub when she was attacked.

Police are continuing to question Andrea's husband Jonathan, who was arrested on Saturday morning in the Isle of Wight.