A woman who works as a part-time nanny in Sydney has appeared in court after being accused of kidnapping offences dating back to Chile’s Pinochet dictatorship.

Adriana Rivas faced an extradition hearing in Sydney on Wednesday over her alleged role in the 1976 killing of a Communist party leader who was held in a secret prison before he was suffocated and thrown into the ocean.

Australian attorney general Christian Porter, who has responsibility for extraditions, said the 66-year-old was arrested in Sydney on Tuesday at the request of Chile.

The country’s supreme court had requested the extradition of Rivas in 2014, based on charges that she kidnapped seven people in 1976 and 1977, including the Communist party leader. The alleged victims have never been found.

Rivas did not apply for bail when she appeared in the Sydney central local court on Wednesday in a video link from a Sydney police cell. She was granted an adjournment until 1 March to get legal advice.

Rivas was an assistant to Manuel Contreras, the head of the dirección de inteligencia nacional (Dina) secret police during General Augusto Pinochet’s military dictatorship.

Chilean chief of the secret police, Manuel Contreras. Photograph: Cris Bouroncle/EPA

She moved to Australia in 1978 but was detained during a visit to Chile in 2006. Rivas was released after some months on probation and fled to Australia in 2009.

Rivas has been working as a part-time nanny and a cleaner in Sydney’s eastern suburbs, Australian Broadcasting Corporation reported.

Chilean-born lawyer Adriana Navarro said the extradition process had been complex and had been interrupted by a change in Chilean governments. Australia and Chile have had a bilateral extradition treaty since 1993.

“There’s been a number of technical obstacles along the way because the Chilean system of law is completely different to the Australian system,” Navarro said. “That’s why it’s taken five years.”

Navarro said the Chilean diaspora in Australia was ecstatic about Rivas’s arrest. “There’s about 45,000 Chileans here and the majority of us, including myself, came to Australia fleeing the Pinochet dictatorship,” Navarro said.

In 2014, Rivas told Australia’s Special Broadcasting Service that she was innocent of the charges, but defended the use of torture in Chile at the time as necessary. “They had to break the people – it has happened all over the world, not only in Chile,” she said.