One suspect had delivered funds "to a foreign group that uses terrorism to reach its aims" and that his beliefs "could affect security," according to a public prosecution statement.
"The first suspect has admitted delivering money to that group abroad, while the second has denied it… Both suspects have been accused of cooperating with a terrorist group abroad and financing a terrorist group."
The statement added that the first suspect would be held in custody for 15 days. The second man was released on bail on Saturday.
The detained suspect has been identified as Adel Saleh, a supporter of the National Justice Movement (NJM) which groups independent and Islamist activists, according to the group’s chief Abdullah Hashem.
Hashem identified the bailed suspect as NJM member Ali Mattar.
"Saleh disappeared about two weeks ago when he was supposed to be travelling to India, but he never left Bahrain according to airport records. It was revealed later that he was under arrest," Hashem told AFP.
"The charge is weak and has no credibility. The release of the second suspect testifies to that," said Hashem, a lawyer.
In the late 1980s Mattar travelled to Afghanistan to "take part in relief work," an NJM official told AFP requesting anonymity.
Designated by Washington as a major non-NATO ally, and home to the US Navy Fifth Fleet, Bahrain recently introduced tough new anti-terror laws despite strong opposition from local rights groups.
In January five Bahrainis were jailed for six months for belonging to Al-Qaeda and plotting attacks.
The five — defended in court by Hashem — were accused of planning "enemy actions" against another state and belonging to a "banned organisation."
