Amnesty International said on Wednesday Saudi authorities have released a Jordanian reform activist who had been held since the beginning of the year in a case that drew concern over his rights.
"Khalid al-Natur, who had been held incommunicado in Saudi Arabia since 6 January was released on 7 April," Amnesty said.
"Throughout his detention, he was denied access to family and lawyers, and was not charged with any offence."
Natur, a website developer, was detained after he and four associates arrived at Riyadh airport on a business trip, according to Amnesty.
The other four "were told they would risk a similar fate if they did not leave the airport immediately," the London-based watchdog said.
"He had been initially held at the General Investigation Directorate's prisons in Riyadh, run by the Saudi Arabian interior ministry, before being moved to Al-Hair prison for the last two weeks of his detention," the London-based watchdog said.
"He was held in solitary confinement for a total of 25 days and was only permitted time outdoors one month after his initial arrest. There has been no formal statement issued by the Saudi Arabian authorities confirming or explaining the reasons for his detention."
Jordanian officials were not immediately available for comment.
Amnesty said Natur had been arrested last year near the Saudi consulate in Amman for insulting a security officer during a protest "against Saudi Arabia's involvement in Bahrain."
Bahraini security forces, backed by Saudi and other Arab troops, bloodily crushed a month-long pro-democracy protest in March 2011.