Security forces in Bangladesh have released the younger son of former Prime Minister Khaleda Zia, official sources have told the BBC.
Khaleda Zia may go into exile in Saudi Arabia
Arafat Rahman was taken from Khaleda Zia's home in Dhaka, by army forces in a pre-dawn raid on Monday.
His release comes amid mounting speculation that it was part of a deal with the government under which Ms Zia's family would go into exile.
Khaleda Zia's elder son, Tarique Rahman, was also arrested last month.
More than 160 suspects have been held from both of the main political parties in a government anti-corruption drive under a state of emergency imposed in January.
Unlike Tarique Rahman - whose case was suspended for six months by a High Court ruling on Tuesday - Arafat Rahman was not involved in politics.
Leading English-language newspapers including the Daily Star and the New Age reported that Arafat Rahman's release was part of a "negotiated deal" with the government.
"She will be leaving the country for Saudi Arabia in a couple of days. Initially she will be leaving with a one-month visa to perform Umrah [a minor pilgrimage to Mecca] and her permanent residence there will be finalised upon reaching the kingdom of Saudi Arabia," the Daily Star said, citing a senior government source.
"Everything has been finalised... now only the formalities, including getting a visa, remain to be completed," it said, adding that the younger son would leave with his mother and the elder brother would follow later.
"Zia has agreed to leave the country but she is taking her time," an unnamed aide of Khaleda Zia told the AFP news agency.
Khaleda Zia has been under virtual house arrest since last week.
"The army held several round of negotiations with her. The release of Arafat Rahman and halting of the case against Tarique Rahman were part of that process," the aide told AFP.
The caretaker government is backed by the army
Government officials and leaders of Khaleda Zia's Bangladesh Nationalist Party (BNP) were not available for comment.
Private ATN Bangla television reported that joint military and police forces carried out a massive search inside Khaleda Zia's house on Monday, while senior officials talked to her and her son for a "long time" before taking him into custody.
It said last month, security officials had searched Arafat Rahman's advertising firm, Adsign, and arrested one of his partners from the office on graft charges.
'False and fake'
The military-led caretaker government has launched a vigorous drive against corruption after its leader, Fakhruddin Ahmed, imposed a state of emergency and cancelled national elections planned for 22 January.
Arafat Rahman was not involved in politics
Ms Zia's Awami League rival Sheikh Hasina - who has been charged with murder and extortion - has meanwhile reiterated her intention to return home from the US to contest what she called the "false and fake cases" against her.
Sheikh Hasina told the Reuters news agency that she would leave Washington for London on Wednesday and intended to travel on to Dhaka at the week-end.
She said she did not fear detention or physical harm.
"They can do whatever they like, but I know my conscience is clear, I haven't done anything wrong, and I haven't committed any crimes," she said.
"They filed cases and more cases maybe just to punish me."
Leaders of Hasina's Awami League said they were preparing for a legal battle over the charges laid against her.
But some officials, who asked not to be identified, said the government might also want Sheikh Hasina out of the country as well as Khaleda Zia.