A much-loved English teacher found a flatmate online and invited him to move in with her.

Within four weeks, the new housemate had killed Annette Brennan and threw her body into a green waste bin in an “extremely callous act”, a court has been told.

He swapped bins with a neighbour and left the 67-year-old outside another property on bin day.

By the time waste workers found the teacher’s remains, days later at a tip in Melbourne’s north, Ms Brennan’s body was so badly mutilated that a cause of death could not be found.

Her killer, Stephen Fleming, could be released from prison in less than a decade after he accepted a sentence indication and pleaded guilty to manslaughter, a few months before a trial was due to begin.

He refused to board a prison bus to attend Melbourne’s Supreme Court on Monday, where Ms Brennan’s loved ones attended as their statements were read out.

Fleming, 48, instead appeared via video link from prison.

Several of Ms Brennan’s close friends attended court on Monday, with prosecutor David Glynn reading statements from three of them.

They included Nanette Austin, to whom Ms Brennan had expressed frustration about Fleming in the days before he killed her.

“Annette’s death was a huge shock … no one should die like that, stuffed in a wheelie bin as trash,” Ms Austin said in a statement.

Ms Brennan had told Ms Austin “he needs to go” about Fleming, after confiding in her over coffee that he had not paid rent for two weeks and had been in contact with their landlord, Mr Glynn said.

Two weeks later, Fleming contacted their landlord to ask for Ms Brennan to be removed from the lease, and for him to be added to it.

Ms Brennan told her sister Fleming was “a bit strange” and had put a lock on his own bedroom.

Prosecutors say Fleming killed Ms Brennan on July 1, and put her body in a bin before cleaning the inside of their share house to destroy evidence and moving into another home about three days later.

His DNA was found on the handles of the bin and on gloves found inside it.

“The offender knew or was aware of what would happen to the deceased’s body when he disposed of it, it was a very grave disrespect of that body,” Mr Glynn told the court.

“It’s an extremely callous act, literally shocking.”

He said this aggravated Fleming’s offending, as did his killing of a vulnerable woman in her home where she should have felt safe.

Fleming has a criminal history, including reckless conduct involving police, and was on a community corrections order at the time.

His barrister Michael McGrath said Fleming’s guilty plea should afford him a discounted sentence, and his psychiatric and drug abuse problems would make his time in prison more burdensome.

Friends spoke of Ms Brennan as a much-loved “kind, intelligent and community-minded” woman, who was due to begin a new job teaching English as a second language the month she was killed.

“Her death has left me devastated and grief-stricken. I have many unanswered questions,” Sally Jamieson, a friend of 14 years, said in a statement.

Fleming was told he must come to court for his sentence on October 29.