Mattar Ibrahim Mattar is one of two members of Bahrain's opposition Al Wefaq party who have been arrested by authorities in the Gulf country.
Mattar is considered a moderate critic of the Sunni-led Bahraini government, and has worked closely with human rights organisations and journalists to uncover violations committed by the government since it launched a crackdown on anti-government protests.
Al Jazeera's correspondent in Manama, who cannot be named for security reasons, spoke to him.
