Facebook Inc's independent oversight board demanded more transparency from the social media giant on Thursday, saying the company was not "fully forthcoming" on how it deals with certain high-profile user accounts.

The comments follow a Wall Street Journal report last month that said millions of Facebook accounts belonging to celebrities, politicians and other high-profile users were exempted from some internal checks.

The board said that Facebook has not been transparent with the company's 'cross-check' system, an internal program the social media network says is used to double-check enforcement actions against certain users.

"Facebook needs to commit to greater transparency and to treat users fairly," the board said in a tweet.

In relation to its May decision to uphold the indefinite suspension of former U.S. President Donald Trump's account after the Jan 6. riot, the board said when Facebook referred the case, it did not mention the cross-check system until it was asked.