Foreigners facing deportation from Switzerland will now be confronted by police officers armed with controversial taser stun guns. The gun discharges up to 50,000 volts, paralysing the victim.

Officers will only be allowed to use the weapon as a last resort, to immobilise violent suspects, including foreigners being sent abroad.

Switzerland's decision to issue the weapon has been strongly criticised by Amnesty International. Its Swiss office said it was a scandalous move, not worthy of the country.

But Liberal MP Didier Burkhalter said the taser could be useful in certain cases. He said one would-be suicide was saved by being knocked unconscious.

Critics claim dozens of deaths around the world can be linked to taser shootings. A 40-year-old Polish man, Robert Dziekanski, died at Vancouver airport after becoming confused and police decided he was dangerous.