A Malaysian was sentenced to more than 10 years' jail and three others were charged over insults against Islam and the Prophet Muhammad on social media, police said on Saturday.
The sentence is believed to be the harshest such penalty on record in the Muslim-majority country, where concerns over racial and religious tensions have grown in recent months.
Inspector-General of Police Mohamad Fuzi Harun said in a statement the person, who was not identified, had plead guilty to 10 charges of misusing communication networks.
The offence carries a maximum penalty of one year in jail or a fine of up to 50,000 ringgit ($12,228) or both.
The sentence was meted out consecutively, Mohamad Fuzi said.
Another social media user had also plead guilty and a sentencing hearing would be held on Monday. Two others had plead not guilty and were being held without bail.
All four were charged under laws against causing racial disharmony, incitement, and misusing communications networks.
"The police advise the public not to abuse social media or communication networks by uploading or sharing any form of provocation that can affect religious or racial sensitivities, causing racial tensions within this country's diverse community," Mohamad Fuzi said.
On Thursday, minister in charge of religious affairs Mujahid Yusof Rawa said the Islamic Affairs Department had set up a unit to monitor writings and communications insulting Islam and Muhammad.
He said the ministry would not compromise on any acts insulting the religion and called for punishments against those found guilty of such.