Stern action must be taken against those who slander Prime Minister Najib Abdul Razak and the government over the 1Malaysia Development Berhad (1MDB) issue.
Umno Supreme Council member Ismail Sabri Yaakob said those who referred to the blog Sarawak Report should be hauled up as nobody is above the law.
They include those exposed by Xavier Andre Justo, a former executive of PetroSaudi International Ltd (PetroSaudi).
He said this was necessary as they might be involved in disseminating inaccurate information about business transactions between 1MDB and PetroSaudi.
"Stern action must be taken against them in order to protect national interest," he told reporters after opening the Pahang Quran recital session at the Bera District Mosque in Pahang today.
Ismail Sabri was commenting on the arrest of Justo by Thai authorities on June 23 and charged with blackmailing PetroSaudi, as reported by the Thai media and verified by the oil company.
The agriculture and agro-based industry minister said Justo's arrest should make the public wary of the evil agenda of some parties.
"We should trust the government and the minister’s explanation and not believe unsubstantiated sources such as the Sarawak Report and The Edge .
"When the 1MDB issue erupted, many people believed in The Edge, which frequently reported biased news and was criticised for sabotaging the economy."
He reminded the people not to believe information in social media or from bloggers but to refer to the authorities for verification.