The Pakistan opposition politician, Imran Khan, has been released from prison in southern Punjab where he has been held under anti-terrorism laws.
The former cricketer was arrested by police last week after attending a protest at Punjab University in Lahore.
On Monday, Mr Khan began a hunger strike in protest at his detention.
He is demanding the restoration of the constitution and the reinstatement of supreme court judges who were sacked after emergency rule was declared.
Mr Khan's release comes a day after Pakistani authorities freed more than 3,000 people who were detained under emergency regulations imposed by President Pervez Musharraf on 3 November.
A spokesman for the interior ministry said many others would be released soon.
A senior leader of Mr Khan's Tehrik-i-Insaf party, Omar Cheema, told the BBC that he had been released from Dera Ghazi Khan jail on Wednesday.
The prison's superintendent, Sheikh Inamur Rehman, later confirmed the release, adding that it had been carried out on the instructions of the provincial government at 1945 local time (1445 GMT).
Imran Khan's sister, Allema, said she was concerned by his health
"I personally saw him off at the prison gate," he told the AFP news agency.
The BBC's Chris Morris had travelled to the prison with three of Mr Khan's sisters earlier on Wednesday, only hours before his unexpected release.
After visiting him inside, Mr Khan's sister Allema confirmed he had eaten no food since Monday and drunk as little as 100ml of liquid over the past two days.
She said her brother appeared rather weak and that they were very concerned by his deteriorating health.
"But he chided us for showing weakness and he said we should urge the youth of Pakistan to go on a token hunger strike to press for the restoration of the judiciary," Ms Khan added.
Our correspondent says Mr Khan's family were as surprised as anyone by his release.
When 3,000 detainees were released on Monday, the Pakistani interior ministry said that anyone who had been charged would not be released anytime soon.
Mr Khan's release may therefore be partly because his detention was making waves internationally and causing embarrassment for the government, our correspondent says.
While he may not be one of the leading politicians in Pakistan, Mr Khan is a known name around the world, he adds.