London: The family of a woman strangled by her former boyfriend has called on the home secretary, Theresa May, to set up a Stephen Lawrence-style public inquiry to examine why victims of domestic violence are still not getting sufficient protection from the police and other government agencies.

As a highly critical report by the police watchdog is published today, the family of Maria Stubbings told the Guardian that nothing short of a formal inquiry would prevent another family having to experience the failures by Essex police that contributed to her death.

Stubbings was strangled to death and dumped in the downstairs toilet of her home in Chelmsford, Essex, in December 2008 by her former boyfriend Marc Chivers. The police knew he had killed before, and that he had served time in prison for assaulting Stubbings.

Yet by the time that Chivers left prison, Essex police had disabled a panic alarm they had installed in her house, and failed to carry out any risk assessment when they did so - one of a number of failings highlighted by the Independent Police Complaints Commission.

Manuel Fernandez, 42, Stubbings’s brother, said his sister’s death must be a “catalyst for change” and an inquiry was needed to make sure that took place. “If there were ever a case that is an example of the state failing to protect a woman, then it is this case,” he said.

“Since her death, there has been a degree of rhetoric about how things have changed. And yet there is a long list of cases like Maria’s that continues to grow. How can this continue?”

When Stubbings called for help on another occasion after Chivers turned up at her home and stole her medication, the report of the incident was downgraded from domestic violence involving a “very high-risk victim” to a “burglary”.

In the intervening days, police made several ineffectual attempts to contact Stubbings, including one visit where they turned up at her home to find Chivers in the house and passed him a note asking her to call them.

When police finally realised the danger Stubbings was in - eight days later - they arrived at her home to discover her body hidden under a pile of coats in the downstairs toilet. Chivers was still in the house with Stubbings’ 15-year-old son, Bengi, whom he was closely watching in case the boy found his mother’s body.

Now 19, Bengi said: “It is horrific to discover the extent of the police’s failings and hard to understand how they got it so wrong. The risk to my mum was clear. I don’t want other women and other children to go through an experience like that. We all deserve help and protection when we’re in danger - and they knew the danger.”

The family’s lawyer, Sarah Ricca, of Deighton Pierce Glynn, believes the cases illustrate institutionalised discrimination against women. “What we need to address this is a Stephen Lawrence [-style] inquiry for women,” she said.