Several opposition parties in Catalonia are pushing for an inquiry into a 2006 clash between police and party-goers, after Catalan public television aired a documentary alleging police torture and a cover-up of the facts in the aftermath of the event.

Recent days have seen renewed debate across Catalonia about the events that took place on the night of 4 February 2006, after Barcelona police broke up an outdoor party in the heart of the city. In the violence that ensued, one police officer was left quadriplegic and five people were detained.

Joan Clos, then mayor of Barcelona, said the officer had been injured as a result of a potted plant thrown from the roof of a nearby building. Days later the story was changed and police accused three people of throwing a rock at the officer. Two others were accused of hurling a fence at the officers.

The documentary Ciutat Morta or Dead City, directed by Xapo Ortega and Xavier Artigas, looked into the eight-year old case, putting a spotlight on the stories of the accused. “Justice for me has lost any value. I want revenge,” said Chilean Rodrigo Lanza, one of the three accused who served five years in prison for allegedly throwing a rock at the officer. Lanza, who maintains his innocence, claims in the documentary that he was severely tortured by police while waiting for trial.

Patricia Heras from the documentary Ciutat Morta, or Dead City, directed by Xapo Ortega and Xavier Artigas Photograph: PR

Patricia Heras and Alfredo Pestana were arrested at Hospital del Mar hours after the clash, accused of throwing a fence at the police. The pair, who said they wound up at the hospital after Heras fell off her bike, were lumped in with the other suspects in the case, alleged the documentary, because of their “punk” style. Despite the declaration of the ambulance drivers who said they had picked up the pair in another part of the city before bringing them to the hospital, Heras was sentenced to three years in prison.

In 2011, while out on a pass from prison, Heras killed herself. In her diary, read throughout the documentary to convey her story, she wrote: “abuse of power, physical and mental aggressions, illegal detentions, tortures … I find it incredible that I can be part of this deadly joke just because my look is not normal”.

On Saturday evening, after more than half a million people tuned in across Catalonia to watch the documentary, social media lit up with reaction and about 200 people spilled out into Barcelona’s Sant Jaume plaza to demand that the case be reopened. Gathered around a sign reading “Enough with brutality, enough with impunity”, they lit candles in an improvised memorial for Heras.

Several opposition politicians have since joined them in calling for an inquiry into the handling of the case. “It would be normal,” said Miquel Iceta of the Catalan Socialist party, who was governing Barcelona in 2006 when the clash occurred, for prosecutors to open the case given the “social alarm” it has set off in recent days.

The city of Barcelona said it had sent public prosecutors a copy of the documentary, with a letter encouraging them to evaluate whether the case should be reopened. In an interview with Spanish radio Cadena Cope, Barcelona mayor, Xavier Trias, said the “city would make all efforts” to contribute towards building a clear picture of what happened that night. “The documentary is done from a certain point of view, but I think it takes aim at situations, that if proven true, aren’t acceptable,” said Trias.

The aim of the documentary was to ask “who watches over authority”, director Aries told the Guardian. “We all have an ideology and that is what guides this supposed objectivity. However, this story has been explained with utmost rigour and we have always defended that the facts that we tell are completely accurate and narrate the truth.”