Zurich-based human rights advisor and UN special rapporteur on torture Nils Melzer said on Monday that Switzerland “must respect the absolute ban on torture” by not extraditing Nexane Txapartegi to Spain, news agencies reported.
In late March the Swiss federal justice office approved the extradition request but that decision must still be confirmed by the federal criminal court after Txapartegi appealed.
Txapartegi fled Spain in 2007 after being convicted by a Spanish court for having acted as a middleman for Basque militant group ETA in 1998.
She was arrested in Switzerland in April last year and contested a request for her extradition by saying she was tortured on her original arrest in Spain in 1999.
She denied the charges against her and said they were based on information extracted from her under torture in Spain.
She claims to have been suffocated with a plastic bag, raped, beaten and subjected to electroshock treatment and sleep deprivation.
“It was only after five days of brutal interrogation that Txapartegi confessed to having participated in the criminal activities of ETA,” said Melzer.
The federal authorities “do not seem to have taken into account” the witness accounts and medical reports that validate the allegations of torture, he added.
According to European human rights laws a person cannot be extradited if their statements were given under torture.
However in making its judgement in March the federal justice office said it had examined all the necessary documents and concluded that the extradition was not a violation of her fundamental rights. There was no evidence that the Spanish authorities had not taken Txapartegi's claims of torture seriously, it said.
The decision was criticized by human rights groups including Amnesty International Switzerland who said her allegations were credible.
The group humanrights.ch claimed it was a political decision, saying Switzerland did not wish to stigmatize Spain as a country that uses torture.
Later that month the Swiss federal migration office then refused Txapartegi's request for asylum.
ETA announced a ceasefire in 2011 and earlier this month handed French police a list of weapons caches.
The Spanish government blames the group for over 800 deaths since 1968.