Ebrahim Sharif, who headed the opposition group Waed, was freed on June 19 after spending four years in jail over his involvement in the 2011 anti-government protests, AFP reported on Wednesday.
But he was re-arrested three weeks later for “violating the law”.
Public prosecutor Wael Bu Allay, in a statement carried by state news agency BNA, said an unnamed individual was accused of “promoting political change through forceful means and threats and inciting hatred against the political regime”.
Judicial sources in Bahrain confirmed that the statement, which gave an August 24 date for the trial to open in the Higher Criminal Court, was referring to Sharif.
It accused Sharif of promoting “violent disorder” in a “direct attempt to undermine stability in the kingdom and overthrow the regime”, adding that he would remain in custody.
Sharif played a prominent role in the month-long protests and was later among a group of 20 activists tried for plotting to overthrow the rulers of Bahrain.
Opposition sources say the activist was taken back to prison after he criticized the government during a ceremony for a victim of the unrest that has rocked the kingdom.