BEIJING (AP) ― Outspoken Chinese artist Ai Weiwei said Wednesday he feels like he has paid a ransom, after depositing $1.3 million into a government account while he contests a huge tax bill months after being held in police detention.

Chinese tax authorities say Ai’s design firm, Beijing Fake Cultural Development Ltd., owes 15 million yuan ($2.4 million) in back taxes and fines. Ai disputes the government’s tax-evasion allegations and says he does not even own the company involved.

The guarantee paid late Tuesday was required by the local tax bureau in order for him and the company to challenge the tax bill, which was levied on his company months after he was released from police detention.

“It’s more or less like I was a hostage half a year ago, now I paid the ransom and I feel I have been robbed,” Ai told reporters as he was leaving his studio to visit the Beijing Local Taxation Bureau and fill in paperwork for the guarantee.

They now have 60 days to challenge the tax bill ― which Ai’s supporters have called an attempt to silence a high-profile government critic.

“We must take the legal way, as a citizen, a person’s innocence is linked to a nation’s innocence. We are not doing this for ourselves, the legal system needs to be fair and just, it needs to be transparent and fair. Only in this way will there be hope for this country,” Ai said. “I hope we can prove my innocence” and that of the company, he said.

On his visit to the tax bureau, Ai wore a T-shirt with a picture of himself in a missing person poster with the word “Found” stamped on the bottom corner ― a reference to his detention earlier this year and subsequent release in June.