BEIJING — Ai Weiwei announced on Instagram that he got his passport back Wednesday, four years after it was confiscated by Chinese authorities.

The artist and government critic posted a photo of himself holding a Chinese passport with the caption, "Today, I got my passport."

Ai was detained by authorities for about three months in 2011 but not charged.

Ai's design firm later was slapped with a $2.4 million tax bill, which he fought unsuccessfully in Chinese courts.

Ai's representative confirmed the passport had been returned, but didn't immediately respond to further questions.

Chinese authorities often deny passports to dissidents who might embarrass the ruling Communist Party overseas.

Ai's work has been shown worldwide, making him one of best-known Chinese dissidents.

Before his detention, Ai had spoken out about a number of national scandals, including the deaths of students in shoddily built schools that collapsed during a massive earthquake in 2008.

The government has blacklisted him from any mention in state media, and he is not allowed to post anything on China's social media.