Switzerland has suspended all flights removing rejected asylum seekers after an asylum seeker on a hunger strike died in shackles on the tarmac at Zurich airport as he was being taken to the plane that would return him to Nigeria.

The 29-year old man, a convicted drug dealer, had been on a hunger strike for several days.

Swiss authorities have launched an investigation into the man’s death. Thirteen other Nigerians, who were being deported with the deceased, have accused the Swiss police of inhumane treatment.

"They dealt with us like animals," one, named only as Emmanuel, told Switzerland's Swissinfo Web site. "The shackled our feet, knees, hands, hips arms and torso and made us wear a helmet like those worn by boxers. It was simply impossible to move."

Police have said that they immediately took off the man’s shackles and called for medical assistance when he collapsed.