The five defendants in the notorious Pamplona sexual attack case have had their prison sentences raised from nine to 15 years each after the supreme court found them guilty of gang-raping a woman at the running of the bulls festival three years ago.

The case – known as La Manada, or the “wolf pack”, after the name of the men’s WhatsApp group – shocked Spain, prompted major protests and provoked a fierce debate over the country’s sexual offences legislation.

At the end of their trial in Pamplona in April last year, the five were cleared of gang rape but convicted of the lesser charge of sexual abuse.

Under Spanish law, sexual abuse differs from rape in that it does not involve violence or intimidation.

Defence lawyers had claimed the woman had consented and had let one of the men kiss her. They also argued that 96 seconds of video footage from the men’s phones – showing the woman immobile and with her eyes shut during the attack – was proof of consent.

The prosecution, however, said the victim had simply been too terrified to move.

José Ángel Prenda, Alfonso Cabezuelo, Antonio Manuel Guerrero, Jesús Escudero and Ángel Boza were originally sentenced to nine years’ imprisonment, five years’ probation and ordered to pay €10,000 each to the woman. Guerrero, a Guardia Civil police officer, was also fined €900 for stealing her phone.

But on Friday, the supreme court in Madrid overturned the lower court’s verdict, ruling that the men had committed rape rather than sexual abuse.

It said the victim had been subjected to “a genuinely intimidating scenario in which she never consented to the sexual acts perpetrated by the accused”.

Explaining its decision to find the five guilty of rape, the court added: “This intimidating situation led the victim to adopt an attitude of submission, doing what the perpetrators told her to do, despite the distress and intense strain … The accused took advantage of this to commit acts against the victim’s freedom, among them at least 10 sexual assaults consisting of oral, vaginal and anal penetration.”

Earlier, the public prosecutor Isabel Rodríguez had argued that violence and intimidation had been used in the assault, saying: “You can’t ask victims to act in a dangerously heroic way.”

The defendants were sentenced to 15 years in prison, forbidden from contacting or approaching the victim for 20 years, and ordered to pay her €100,000. Guerrero was sentenced to a further two years for the phone theft.

The original proceedings had also been criticised because the judges accepted into evidence a report compiled by a private detective hired by some of the defendants. The detective had followed the woman over several days and produced photographs of her smiling with friends.

Spain’s acting deputy prime minister and equalities minister, Carmen Calvo, said the supreme court’s decision “recognised the credibility of the victim”.

In a tweet, she said the verdict was in line with the government’s proposals to change the law to distinguish between rape and sexual assault, and sexual abuse.

Viviana Waisman, the president of the human rights NGO Women’s Link, said the verdict was very important.

“It sends a clear message that judges must apply the law without gender stereotypes and that when victims of sexual violence come forth, they must be believed instead of questioned – and that the system needs to focus on investigating the accused and not the victims,” she said.

The convicted men can appeal to the Spanish constitutional court and then to the European court of human rights.