The Malaysian government is investigating an international atheist organisation after a picture of a meeting held by the group in Kuala Lumpur went viral.

Atheist Republic, a Canada-based non-profit organisation, often stages meet-ups in larger cities, and last week posted a picture on Facebook of people attending the Atheist Republic Consulate of Kuala Lumpur annual meeting.

The post said the gathering “was such a blast!” and shows a room full of people smiling with their arms in the air. Many are making hand gestures. “Atheists from all walks of life came to meet one another, some for the very first time… each sharing their stories and forming new friendships that hopefully last a lifetime! We rock!” it read.

Malaysia is a multi-ethnic and multi-religious country where apostasy is not a federal crime, but critics say deepening fundamentalism within the Muslim majority is threatening religious freedoms, Reuters news agency reports.

Malaysian states that have their own laws regarding Islamic affairs do now allow Muslims to formally renounce their faith, and people are instead fined, jailed or sent for counselling.

Some claimed that Muslim apostates were involved in the Malaysian chapter of Atheist Republic, which has reportedly sparked uproar among some Muslims.

Members of the atheist group are reported to have received death threats on social media.

The group is being investigated by Malaysia’s Federal Territories Islamic Religious Department to determine whether any Muslims were involved in the meeting.

Dr Asyraf Wajdi Dusuki, the country’s deputy minister who oversees religious affairs, told reporters: “If it is proven that there are Muslims involved in atheist activities that could affect their faith, the state Islamic religious departments or Jawi could take action,” New Straits Times reported.

“I have asked for Jawi to look into this grave allegation.”

Mr Wajdi told Reuters that the government will determine whether any Muslims were in attendance at the atheist meeting and if they have been involved in spreading atheism, which he claimed “can jeopardise the aquidah [faith] of Muslims”.