FIFA presidential candidate Prince Ali has been cautioned for speaking about rival Sheikh Salman ahead of Friday's vote to decide Sepp Blatter's successor.
The pair are two of five candidates to replace the outgoing Blatter, with Sheikh Salman the current favourite to be named as the new head of world football's governing body.
Prince Ali had reportedly questioned the role of Sheikh Salman in the Bahrain uprising of 2011, with the latter quickly denying any involvement in the alleged torture and imprisonment of pro-democracy demonstrators.
Prince Ali, who had suggested that the elections should be postponed after his request for transparent voting booths was turned down by FIFA, has declined to comment further on his rival after being sent a disciplinary letter from the head of the electoral committee Domenico Scala.
"I am not going to comment on any other candidate. In fact, I was cautioned by the chairman of the electoral committee that I should not be commenting when I answered some very legitimate questions before," the Jordanian is quoted as saying by PA.
"What I'm focused on is the election itself. I'm very optimistic and happy with the way things are going."
Gianni Infantino, Tokyo Sexwale and Jerome Champagne are the other candidates hoping to become the next FIFA president.