Women have been killed by at least 15 serving or former police officers in the UK since 2009, new figures reveal.

The majority of the women killed by former officers had been their partners, according to data from the Femicide Census first reported by the Times.

Other cases shown in the data, which tracks the killings of women by men in the UK, were a killing for financial gain and another where a former police officer smothered his mother.

The murder of Sarah Everard by Wayne Couzens, who was a Metropolitan police officer, had seen a renewed focus on attacks on women involving the police.

Vigils held on Clapham Common in south-west London after her death on 3 March had been disrupted by the police, who controversially arrested women and dispersed mourners.

Couzens, 48, a diplomatic protection officer who carried a firearm, admitted murdering Everard, 33, and will be sentenced at the Old Bailey this week. He was sacked by the Met after his admission of guilt.

He had also admitted to kidnap and rape during an incident where he had driven the marketing manager from London to where her body was ultimately discovered, in woodland near Ashford in Kent.

Speaking after Couzens admitted the offences, the Met Commissioner Cressida Dick said: “I have 44,000 people working in the Met. Sadly, some of them are abused at home, for example, and sadly, on occasion, I have a bad ‘un.”

Karen Ingala Smith, a co-founder of the Femicide Census, told the Times that the problem went “way deeper” than what could be described as a “bad ‘un”. An example she pointed to was the scandal of undercover officers engaging in sexual relationships with activists who they targeted.

This month a serving officer in the Met was charged with voyeurism offences.

Ingala Smith criticised “disbelieving attitudes that enable rapists, rather than support rape victims”. She said: “This is not the problem of a few ‘bad ‘uns’ but systemic and institutional sexism. The Femicide Census has shown that even murder of a woman was not a one-off.”

The census data, which included Couzens, showed 10 murders by police officers, former police officers and a former special constable since 2009.

Other cases were classed as manslaughter and included Dorset constable Timothy Brehmer, who had strangled a woman he had been having an affair with after she exposed him to his wife. Brehmer was cleared of murder.

In most cases, which usually involved former officers, the women had been intimate partners, formerly intimate partners or the spouse of the perpetrator.

Cases included Ivan Escak, who was jailed for life in 2013 for murdering his estranged wife by stabbing her 11 times at her hair salon in Ashford, Kent.

William Kean, a former special constable with Tayside police, was convicted in 2012 of beating an 80-year-old charity volunteer to death to steal money from her.

In 2011, former detective Peter Foster murdered his partner, a police officer, by hitting her with a baseball bat and stabbing her in the throat.