Another adviser has said Khaleda Zia's release is "at final stages" and that the government will not impose any conditions.
Speaking to reporters Sunday, communications adviser Ghulam Quader however did not give a specific date.
Asked whether she would be released this week, Quader said: "That is difficult for me to say."
Pressed further, he said: "There'll be no conditions. She's being released without any conditions attached."
The adviser only echoed colleague Hossain Zillur Rahman. The latter also said on Saturday that the procedure to release BNP chief Khaleda Zia was "at final stages".
At a briefing again on Sunday, Zillur also refused to speculate on the timing of her release.
Adviser Quader also confirmed that freedom for her son Tarique Rahman was also "being considered on humanitarian grounds".