UAE security personnel sent Brigadier Abd al-Aziz Khalid back to Khartoum on Wednesday to answer five-year-old charges of sabotage.
Former Sudanese attorney-general Umar Abd al-Aati told a large crowd of supporters and journalists that had gathered at the airport that there was no need for concern about the well-being of the former rebel army leader.
Referring to a general amnesty for political opponents issued in 2000, Abd al-Aati said - despite his involuntary return - he would be freed within hours.
"Khalid will be freed tonight or tomorrow. According to the justice minister [Ali Muhammad Usman], he was taken to the security offices only to complete some procedures," the former attorney-general said.
Concern for welfare
But a US-based human-rights watchdog has expressed concern for Khalid's welfare and had appealed to the UAE authorities not to honour the extradition request.
"We believe that the Sudanese government's extradition request is a politically motivated attempt to deny Abd al-Aziz Khalid of his rights to freedom of expression, association and movement," New York-based Human Rights Watch (HRH) said in a 9 November letter.
"Abd al-Aziz Khalid is a respected Sudanese opposition figure who was travelling to the United Arab Emirates on 23 September 2004 to give lectures and hold meetings when he was arrested on a Sudanese government extradition request."
HRH noted that the Eritrea-based armed opposition group which Khalid had commanded - the Sudanese Alliance Forces - is now inactive and in negotiations with the government.