The ex-mayor of an upscale Santiago neighbourhood was arrested and charged on Monday in connection with an ongoing investigation into human rights crimes committed in Chile during general Augusto Pinochet’s 1973-1990 dictatorship.

Cristian Labbe, a retired colonel who also served as an aide to Pinochet and later as mayor of the capital’s Providencia district, is being prosecuted along with nine other former military members and police officers, said lawyers for the government’s human rights department.

Judge Marianela Cifuentes ordered Labbe’s arrest and decided to prosecute him for unlawful association as a member of Pinochet’s notorious DINA secret police.

“The (interior ministry’s) human rights department asked for Cristian Labbe Galilea to be prosecuted for homicide, kidnapping, torture and unlawful association,” said lawyer Rodrigo Lledo, head of the programme’s legal division.

The lawyers said they would appeal the judge’s decision to only prosecute him for unlawful association.

The prosecutions relate to the disappearance and execution of 13 people at the Tejas Verdes military barracks between 1973 and 1974. Among others being prosecuted are Manuel Contreras, the former chief of the DINA secret police, who is already serving time for human rights violations.

Lawyer Gabriel Aguirre said the investigation has established that the DINA was likely formed during those tumultuous days at the barracks, in the coastal city of San Antonio.

The human rights department also said it will seek the collaboration of Brazilian authorities to determine if Labbe learned torture techniques there in 1972-1973, when Brazil was in the grips of its own military dictatorship.

Labbe has said he went to Brazil to take physical education classes and that he gave such classes at Tejas Verdes.

Labbe’s lawyer told local media that Labbe had never tortured, saying to 24Horas TV channel on Monday that Labbe’s “conscience was clear and at ease”.

“His defence says, he says, he didn’t torture anyone directly. But what has been undoubtedly established is that while people were being tortured, he walked around the place acting as a consultant to those tortures,” said Lledo.

Though the coup that ushered in the military dictatorship happened over four decades ago, there has been a recent push to bring more of those accused of human rights crimes to trial.

Last month, the government said it would seek to overturn a controversial law that protects military personnel who committed human rights atrocities during the dictatorship from being prosecuted.

Labbe, a polarising figure in Chilean politics and a member of the right-wing UDI party, has long drawn criticism for his outspoken support of the dictatorship.

In 1996, he was elected mayor of Providencia, an affluent business and residential district in Santiago, serving four tenures until being voted out of office in 2012.

An estimated 3,000 people were kidnapped and killed or disappeared and 28,000 were tortured during the 17-year dictatorship. Pinochet died in 2006 at the age of 91, having never faced a full trial for the crimes committed under his rule.

The investigation into the deaths, including those of three victims whose bodies were never recovered, concluded that all 13 were tortured and executed, some shot to death and others drowned in the Rapel river.

Labbe’s lawyer, Cristian Espejo, expressed surprise over the charges.

“We are very taken aback, because after a long and extensive investigation it was shown that he never tortured anyone, and has not committed homicide,” Espejo told CNN Chile.

Labbe’s defence will seek his release.

Labbe is being held at an army barracks in Santiago.

Six of the other former regime officials arrested are charged with torture and homicide, another with homicide, and eighth with kidnapping and torture.

Inmates were alleged to have been subjected to electric shocks, beatings, burns, having their fingernails extracted, simulated firing squads and other forms of torture at DINA.

He has been a fervent defender of Pinochet, who ruled from 1973 to 1990.