Hashim also wanted to attack the Indian High Commission in the capital of Sri Lanka on April 4.
The National Tawheed Jama’ath imam had a history of racism and calling for Islamic superiority, according to reports.
Sri Lankan press reported in July 2017 that the organisation’s leaders were being prosecuted for making derogatory remarks in a video against Buddha and hurting the sentiments of the Sinhala-Buddhist community.
Hashim also posted YouTube videos in which he preached comments that could be considered incitement.
“For years, the faithful man spread his incitement without being banned,” he said.
In another video, he asked: “What can Sri Lankan Muslims do for Dr Zakir Naik?”
Naik, the president of the Islamic Research Foundation in India, is considered to preach hate and support terrorism.