The judge has rejected an appeal against his sentence of two years in jail for Jose Campos, who had admitted murdering an actress and her child.
The ruling on Tuesday was the first to apply to the appeal in a Spanish criminal court.
It is the latest in a string of high-profile cases involving political figures who have been accused of being involved in violence against the press.
Campos was sentenced to four years in prison and a fine of $30,000 in January 2016 after being convicted of the murder of actress Maria Doria de las Campanas in her Barcelona apartment in March 2015.
He was also convicted of attempted murder of a journalist, the attempted murder and robbery of a film-maker and a robbery.
He said in his appeal that he had only acted as a mediator between the victims and the defendants and was not responsible for the crimes committed against them.
The judge had said Campos should have been jailed for life, given that he was not even involved in the killings.
The appeal against the sentence was brought by lawyers for Campos’ wife and his brother-in-law, who were also involved in a previous trial.
They argued that the judge had violated their rights and had failed to provide proper justice. Judge José Gómez Ocampo, who heard the case, was quoted by Spanish media as saying: “He [Campos] was not a perpetrator.
Campos has always denied the charges and insisted that the case was politically motivated. “
He did not take part in this crime, but he was involved in other crimes that did not come to light.”
Campos has always denied the charges and insisted that the case was politically motivated.
Prosecutors in the case say Campos confessed to the murders after he was arrested in November 2016 after an investigation revealed that his brother had been arrested and jailed on a murder charge.
He has been charged with murder, armed robbery, attempted murder, criminal intimidation, kidnapping, extortion and illegal use of a firearm.