The Metropolitan Police has lost its Supreme Court challenge over a ruling which led to two women who were sexually assaulted by London cabbie John Worboys winning compensation.

The women were raped by Worboys in 2003 and 2007 and when they reported the attacks, the police did not believe them. Worboys continued attacking women until 2009.

The case was pursued to establish legal principles for the future and the women – only identified as DSD and NBV – were never at risk of losing their damages, the Met said.

Lawyers for the Met, backed by the Home Office, said that imposing a duty of care on officers in relation to their investigations would have an adverse impact on operational effectiveness. But on Wednesday,  five justices unanimously dismissed the appeal.

Worboys, a former stripper and adult film star, was found guilty of 19 charges of drugging and sexually assaulting 12 women passengers, in one case raping a woman. He used alcohol and drugs to incapacitate his victims between 2002 and 2008 and became known as the black cab rapist after attacking victims in his hackney carriage. In total, there were more than 100 complainants, though the vast majority were not brought to trial, with the Crown Prosecution Service saying they did not pass the evidential test.

He was jailed indefinitely in 2009, with a minimum term of eight years.

One of the victims, DSD, who was at court to hear the judgment, struggled to hold back tears as she said: “It has been an emotional day. Fifteen years.”

Referring to the police, she added: “Had you done your job properly, there wouldn’t be 105 victims, there would be one. I can take the one. I can’t take the 105.”

DSD was the first of Worboys’ victims to make a complaint to the Met in 2003, while NBV contacted them after she was attacked in July 2007. In NBV’s case, Worboys was quickly arrested as a suspect but released without charge, while in DSD’s case he was never identified.

DSD alleged that she suffered a depressive disorder as a result of her treatment by officers and NBV claimed she endured distress, anxiety, guilt and an exacerbation of post-traumatic stress disorder and depression.

DSD’s lawyer Harriet Wistrich said: “It’s a very, very important judgment – very important for vindicating the rights of my two clients but also for the other victims of Worboys.”

Wistrich says she has been contacted by other alleged victims, including two previously unreported ones from 2002 and 2003 and will be requesting police investigate further and prosecute.

In 2014, after the High Court found that the Met were liable to the women for failures in its investigation, it said that DSD and NBV – who brought their claims under Article 3 of the Human Rights Act which relates to inhuman or degrading treatment – should receive £22,250 and £19,000 respectively.

The Met, with the Home Office – under then-Home Secretary Theresa May who intervened in support, went to the Supreme Court after the Court of Appeal backed the decision.

Sir Craig Mackey, deputy commissioner of the Met, said the force “fully accepts the decision of the court.”

He added: “We have always accepted that serious mistakes were made in this investigation and it was only the courage of the victims coming forward, including these two claimants, that enabled us to finally convict Worboys. We know we should have done more in the initial investigation and today, as we did following his conviction, I unreservedly apologise to the victims we failed.

“The MPS appealed, and this was supported by the Government, because police forces needed absolute clarity on the boundaries of police responsibility and liability for their investigations. We have always been clear that the appeal to the Supreme Court was not based on factual differences between us and the victims, but on the appropriate interpretation of European human rights law.”

Martha Spurrier, Director of Liberty, said: “From the very start this has been a catalogue of devastating failures by the people who are supposed keep us safe.

“Having already let these women down in the most horrific way, the Met could have accepted the High Court’s ruling four years ago. Instead they used taxpayers’ money to drag them all the way to the highest court in the land, with the full backing of the Home Secretary.

“What was obvious from the start is now in black and white – the police are legally required to properly investigate very serious crimes. Instead of focusing their resources on wriggling out of their fundamental duties under the Human Rights Act, the Government and police must now commit themselves to protecting survivors of sexual violence and standing up for victims’ rights.”

Worboys, 60, will remain in prison pending a full High Court hearing on March 13, which is expected to last two days.

Rape Crisis services for women and girls who have been raped or have experienced sexual violence – 0808 802 9999 Survivors UK offers support for men and boys – 0203 598 3898