Bahraini authorities have released prominent rights activist Zainab al-Khawaja on humanitarian grounds after two and a half months behind bars.

The activist's sister, Maryam al-Khawaja, confirmed her release to The Associated Press on Tuesday.

Zainab al-Khawaja is the daughter of well-known activist Abdulhadi al-Khawaja, who is serving a life sentence over his role in Arab Spring-inspired protests in 2011.

A dual Danish-Bahraini citizen, she was detained on March 14 and faced three years in prison on charges related to her participation in anti-government protests, including tearing up pictures of Bahraini King Hamad bin Isa Al Khalifa.

Bahrain's Foreign Ministry announced plans to release her earlier this month on account of her year-old son, who was allowed to stay with her in a special prison ward for new mothers.