Authorities in Spain have re-arrested a Syrian-born al-Jazeera television reporter charged last year with fundraising for al-Qaeda.
Alouni was released on bail because of a heart condition
Tayseer Alouni, a Spanish citizen who lives in Granada, was arrested on Thursday evening on his way home.
Mr Alouni is one of al-Jazeera's best known reporters, and has interviewed Osama bin Laden for the Qatari channel.
Officials are said to have feared that he would flee the country after confirmation that he would face trial.
However, no official reason was given for taking him back into custody.
Spain's EFE news agency reported that the decision was made after a judge linked him to the banned Islamic group, the Muslim Brotherhood.
Mr Alouni was held overnight in police custody in Granada and then transferred to the capital Madrid, the agency said.
Mr Alouni was among 35 people arrested and charged with terror offences in September 2003 under orders from Spanish High Court judge Baltasar Garzon.
He was accused of having links to al-Qaeda and using reporting trips to Kabul, Afghanistan, as a cover for fundraising activities.
Confirmation that he and 20 others would be tried came earlier this week.
Mr Alouni was released last year on bail of 6,000 euros (£4,200 or $7,800), and was not allowed to leave Spain without the court's permission. He also had to report to court weekly.
Al-Jazeera has consistently stood by its reporter since his arrest and has accused the US and Israel of inciting Spain to incriminate him.
Mr Alouni's wife, Fatima, told al-Jazeera that she was surprised at her husband's re-arrest and claimed that Judge Garzon had turned the issue into a "personal affair"