Facebook's Donald Trump ban has been upheld by its Oversight Board.
The company gave the former president a permanent ban from both Facebook and Instagram in January following the Capitol Hill riots.
Now, the Oversight Board has told the social networking site to review its decision and "justify a proportionate response" to bring the punishment in line with a policy "consistent with the rules that are applied to other users of its platform".
Facebook has been give six months to respond.
Co-chair Helle Thorning-Schmidt said in a press conference: "We are telling Facebook to go back and be more transparent about how it assesses these things. Treat all users the same and don't give arbitrary penalties."
In turn, Facebook has confirmed it will "consider the board's decision and determine an action that is clear and proportionate".
In a statement on social media, the Oversight Board said this week: "The Board has upheld Facebook’s decision on January 7 to suspend then-President Trump from Facebook and Instagram.
"Trump’s posts during the Capitol riot severely violated Facebook’s rules and encouraged and legitimized violence.
"The Board also found Facebook violated its own rules by imposing a suspension that was ‘indefinite.’
"This penalty is not described in Facebook’s content policies. It has no clear criteria and gives Facebook total discretion on when to impose or lift it.
"Within 6 months of today, Facebook must review this matter and decide a new penalty that reflects its rules, the severity of the violation, and prospect of future harm.
"Facebook can either impose a time-limited suspension or account deletion."