City Harvest Church co-founder and pop singer Ho Yeow Sun's official website was hacked on Monday morning by a perpetrator signed off as "The Messiah".
In a long message directed at Ms Ho, the hacker threatened to expose her "hidden agenda" and release personal data on her website onto the public domain.
The hacker closes with the statement: "You do not want to displease me any further, especially since I could be the second coming."
The hacked website also made reference to the ongoing trial of six City Harvest leaders for allegedly misusing more than $50 million in church funds. The money is said to have been funnelled into sham bond investments to further the music career of Ms Ho - also the wife of church pastor Kong Hee - and to cover up their tracks.
The site has since been taken down. The church's lawyer Desmond Ong said that this matter has been referred to the police. The church had found out about the website hacking only after The Straits Times approached them for a response.
The Straits Times understands that the hacker may have chosen to hack into the website on Monday as it is the rest day for the church's employees.
He Yao Sun fan club president, Ms Sherlyn Ng, told The Straits Times that the hacking "was a vindictive act that has no backing or substance". She added: "I heard the police are looking into it and I am sure justice will be served."