Bangladesh's army-backed government plans to free former premier Khaleda Zia, a minister said on Sunday, in a bid to avert a boycott by her party of national elections planned for the end of the year.
The announcement came days after ex-premier Sheikh Hasina Wajed was released from nearly a year of detention on graft charges and allowed to fly to the United States for medical treatment.
"We are looking at ways to free her (Zia) on humanitarian and medical grounds," interim commerce minister Hussain Zillur Rahman told AFP.
"It cannot be done overnight. But we're in the final phase of the process," he said.
Zia, the head of the Bangladesh Nationalist Party (BNP), has been held on corruption charges since last September.
Rahman was quoted by BSS news agency as saying the government hoped to "create an atmosphere of confidence among all political parties and an atmosphere conducive to free and credible polls."
Sheikh Hasina's release last Wednesday was part of a political deal with the government aimed at ending a stalemate with the two main parties, her Awami League and Zia's BNP.
Both parties had refused to hold talks to plan for an election in December, aimed at restoring the country to democratic rule, because their leaders - fierce political foes - have been in detention.
Zia, who led Bangladesh twice, was the most recent elected premier, serving from 1996 to 2001. She said she would not go abroad for treatment of acute arthritis and knee problems.
But she has demanded that the government release her two sons, who are also being held on graft charges.
Her lawyer Nasiruddin Ashim said the two sons need medical treatment abroad.
One has severe disc back problems and the other has bad asthma and lung trouble, Ashim said, adding they "haven't had proper treatment in jail for their medical problems."
The ex-premiers have been among more than 150 top politicians held by the government since mid-2007 as part of a corruption crackdown that has also included arrests of top businessmen and thousands of political activists.
The government took power in January last year after political paralysis and unrest blamed on the BNP and the Awami League led to imposition of emergency rule.
The authorities last month kicked off dialogue with parties as part of a roadmap to restore democracy, but the boycott by the BNP and the Awami League threatened to scupper the entire process.
The Awami League agreed to return to the negotiating table and take part in the elections after Sheikh Hasina was released on parole for eight weeks and left the country for treatment of hearing problems in the United States.
Analysts said Hasina's US trip was tantamount to "voluntary exile" for the ex-premier, who still faces at least half a dozen corruption charges and is to be tried in absentia.
The interim government tried to force Sheikh Hasina and Zia into exile last year as part of an effort to clean up Bangladesh's notoriously corrupt political system, but they refused to leave and were put on trial instead.