The National Intelligence and Security Services said the publication, al-Sahafa, would be closed if Editor in Chief al-Nur Ahmed al-Nur did not resign, the Sudan Tribune reported Wednesday.
Al-Nur had headed the newspaper since 2007. Al-Sahafa began publication in 1961.
Security officials did not give the reason for the editor's suspension. However, the newspaper has recently experienced pre-printing censorship and has been barred from publishing articles critical of the government.
Al-Nur said authorities told him he could continue to write for the newspaper, but not as editor in chief.
Security officials also summoned al-Masalami Kabbashi, the Khartoum bureau chief of al-Jazeera, said Mekki Elmograbi, president of the non-government Sudan Press Freedom association.
Elmograbi said Kabbashi was questioned "from morning to evening with some hours for break and prayers."
Sudan officially ended direct press censorship in 2009. President Omar al-Bashir recently praised the country's media, calling it "a vital partner."
He denied any oppression of journalists or journalism.
"We have not banned any pen critical [of government] but only those who took advantage of the freedom for demolition, anarchy and crossing red lines," Bashir said