Khartoum — Amnesty International has called for the release of Sudanese lawyer and human rights activist Asma Ahmed, who has been detained incommunicado by security services since 4 May, warning she is at risk of torture and other ill-treatment.
Agents of the National Intelligence Security Services (NISS) visited Ahmed's family home in the capital, Khartoum, early on 2 May while she was away.
They returned later that day, asking where she was and demanding that she report to their offices as soon as possible.
Following her return 4 May, Ahmed went to the NISS office in Khartoum North and has been held ever since without charge.
The 39-year-old lawyer is a member of the banned opposition party Sudan People's Liberation Movement-North (SPLM-N) active in the Sudanese border states of South Kordofan and Blue Nile.
Ahmed, who specialises in human rights law, has previously defended political prisoners and prisoners of conscience in court, most notably the high-profile human rights campaigner, Jalila Khamis Koko, who was released in January after spending nine months in prison for expressing her views about the Sudanese government.
In a statement extended to Sudan Tribune, the human rights group expressed concerns for Ahmed's health, saying she suffers from diabetes and requires a special diet and regular medication.
Amnesty has called on authorities to charge Ahmed with a recognisable criminal offence or release her without delay.
The group has also urged Sudanese authorities to provide her with any medical attention she may require, a lawyer of her own choosing, and access to her family.
According to rights groups, at least 100 political prisoners remain in detention in Sudan, despite a pledge by president Omer Hassan al-Bashir on 1 April to free all political detainees.
The remaining political prisoners come mostly from the country's conflict-hit peripheries, including South Kordofan and Blue Nile states.
Following the amnesty offer made during Bashir's opening speech to parliament, security authorities freed a number of high-profile activists and opposition members, however, investigations by rights groups show that many more people are still being held by national security or military authorities on the basis of their presumed political affiliations and have not been afforded due process or charged with any legally recognisable offence.
The remaining political prisoners come mostly from the country's conflict-hit peripheries, including South Kordofan and Blue Nile states, where the government has been fighting armed SPLM-N rebels formally aligned with South Sudan since 2011.
In November 2012, security forces in South Kordofan arrested more than 30 women in Kadugli and Deleng, including four with infants. Fourteen were later released last month under restrictive bail conditions, with the remaining women still being held without charge or access to their families or legal representation.
In a joint statement issued last month, Human Rights Watch (HRW), the African Centre for Justice and Peace Studies (ACJPS) and the Human Rights and Development Organisation (HUDO) urged the Sudanese government to allow independent monitors into prisons and detention facilities to account for all remaining political prisoners.
Sudan's 2010 National Security and Intelligence Act provides the state's security apparatus with sweeping powers of arrest and detention for up to four-and-a-half months without charge or judicial review, as well as search and seizure powers.