(AP)—A judge says he has ordered the suspension of the globally popular instant messaging system WhatsApp across Brazil because it has allegedly failed to help in an investigation.

Judge Luiz de Moura Correia ordered the suspension earlier this month, though the service has continued to operate normally. The newspaper Folha de S. Paulo said that is because lawyers appealed the ruling.

The judge would not comment on details of his decision because it is an ongoing case, but a press officer at the Piaui state's Public Safety Department says the case is linked to "sexually graphic photos of children on the app." He spoke on condition of anonymity, citing internal regulations.

WhatsApp did not immediately respond to a request for comment.

WhatsApp does not have an office in Brazil so the judge's order was delivered to cellphone operators.

SindiTelebrasil, the association that represents those operators, said on its website that the suspension could cause "huge losses to millions of Brazilians" who use WhatsApp for personal and professional reasons.