A new global instrument to prevent torture comes into being on Thursday but Switzerland – one of the driving forces behind the initiative – has yet to ratify it.
The Swiss had hoped to be among the first countries to do so, but parliament is not expected to consider the matter for months because of procedural delays.
Switzerland's failure to ratify the optional protocol to the United Nations Convention Against Torture has been a source of frustration for the Geneva-based Association for the Prevention of Torture (APT).
The APT played a central role in drafting the new instrument which foresees unannounced visits by international and national inspection teams to all detention facilities including prisons, police stations, psychiatric hospitals and asylum centres.
The Swiss government provided legal and technical assistance during the draft process.
Swiss parliamentarian Martine Brunschwig Graf, who is president of the APT, said Switzerland had missed an opportunity to send out a strong signal of its stance on torture.
"We need preventive mechanisms in all countries and if you are a country committed to human rights – as is the case with Switzerland – then you have to set an example," she told swissinfo.
Brunschwig Graf said she hoped the protocol would be ratified by parliament early next year, adding that it would be "unacceptable" if this did not happen before the end of 2007.
The APT is also concerned about government proposals for a national body to monitor Swiss detention centres. Countries that ratify the treaty have one year to set up so-called "national preventive mechanisms", which must be independent and be supplied with the means to function effectively.
But according to the association, the model sent out for consultation by the Swiss government falls well short of the mark.
"The structure proposed was one of 12 volunteers, without infrastructure and without specific funding. We have made it clear than we cannot put in place a mechanism which does not have sufficient funding and is not run on a professional basis," said Brunschwig Graf.
The Federal Justice Office told swissinfo that the country's procedural process lay behind the delay in ratifying the treaty and it was not down to a lack of political will.
Spokesman Folco Galli said the consultation procedure on the optional protocol had been completed and officials were now preparing draft legislation that would later be submitted to parliament. He said he expected this to be done later this year.
"It is not simply a question of just ratifying the protocol, we have to guarantee that it can be applied in Switzerland and to do this we have to put in place a national mechanism," he said.
Galli added that concerns raised about the national inspection body would be taken into account during the drafting of the new law.
Costa Rica's ambassador to the UN in Geneva, Luis Alberto Varela Quiros, pointed out that Switzerland was not alone in being slow to ratify the treaty. He said other countries were also bogged down by procedural delays.
swissinfo, Adam Beaumont in Geneva
The optional protocol to the UN Convention Against Torture was adopted by the UN General Assembly in December 2002. Switzerland signed the optional protocol in June 2004 but has not ratified it.
The aim of the treaty is to prevent torture and other forms of ill treatment by establishing a system of regular visits to places of detention carried out by independent international and national bodies.
Swiss detention facilities are already subject to visits by members of the Council of Europe's Committee for the Prevention of Torture.
The Geneva-based Association for the Prevention of Torture was founded in 1977 by Swiss banker and lawyer Jean-Jacques Gautier.
It operates globally to prevent torture and ill treatment.
The APT has campaigned for 20 years for the introduction of the optional protocol.
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