A Peruvian judge ruled Friday that former president Alberto Fujimori cannot for now be prosecuted over alleged forced sterilizations that happened during his administration, because the allegation was not included in his extradition request.

The disgraced ex-leader who is serving a 25-year prison sentence over human rights violations and corruption is being investigated over the forced sterilization of hundreds of thousands of poor, mostly indigenous women during his final four years in power.

In 2007, Chile granted extradition of the ex-president, who led Peru from 1990 to 2000.

Judge Rafael Martinez in his ruling said Fujimori can only be prosecuted over the sterilizations if authorized by the Chilean Supreme Court, which previously green-lighted his extradition.

Prosecution is prevented at present “as these facts are not included among the crimes for which his extradition was authorized,” Martinez said.

Martinez was tasked with deciding whether the 83-year-old Fujimori could be brought to trial by the 1,317 plaintiffs in the sterilization case, which began in 2002 but has been shelved and reopened several times.

An estimated 270,000 Peruvians, many of them indigenous people who did not speak Spanish, underwent surgery to have their fallopian tubes tied as part of a family planning program implemented under Fujimori.

The program sought to reduce the birth rate and boost economic development. The surgeries resulted in the death of 18 women, according to official data.

The judge has not yet ruled on the other six co-defendants in the case including three former ministers of health.