A British court blocked the deportation of an Algerian who had been cleared of plotting to launch a terrorist poison attack on London.
Justice John Mitting, chairman of the Special Immigration Appeals Commission, said it was decided Mouloud Sihali was not a risk to national security.
His immigration status, however, remained uncertain, Mitting said.
Sihali, 30, who had been charged with taking part in a plot to spread the poison ricin in London, was acquitted by a jury.
He was freed on bail whose conditions required him to live at a certain address and report weekly to immigration officials.
Appeals by three other Algerians - identified as U, W and Z - were dismissed but their cases are to go before the Court of Appeal.