A judge on Tuesday suspended the WhatsApp smartphone messaging service across Brazil, where it is hugely popular, for failing to surrender user data in a police investigation, the court said.
"WhatsApp is blocked across the whole national territory," a spokesman for the court in Rio de Janeiro told AFP.
WhatsApp, owned by Facebook, has clashed several times with Brazilian courts after refusing to give access to police.
The 19-page ruling said that Brazilian telephone operators must "immediately suspend" WhatsApp services and also said that continued non-compliance would see the Facebook company fined 50,000 Reais ($15,265) a day.
The decision by Judge Daniela Barbosa Assun??o de Souza in the southeastern state of Rio de Janeiro applies to Brazil's five wireless carriers. The reason for the order was not known due to legal secrecy in an ongoing case, and will only be lifted once Facebook surrenders data, Souza's office said.
Shortly after the ruling was filed, WhatsApp messaging continued to function in Rio, however. It was not clear how quickly the order would be fulfilled.
A spokeswoman for WhatsApp said she had no immediate comment.