Police are looking into a report of a video showing a group singing the national anthem against a backdrop of the Malaysian and Israeli flags.
In a statement issued by the Petaling Jaya district police headquarters, they said a report was made by a man at about 11.2opm on Nov 29.
The man said he had seen a 47-second clip shared in a WhatsApp group of several individuals singing Negaraku alongside the flags of both countries.
"Early investigations found that the incident occurred in September, when a group of locals were visiting another country with a travel agency," the police said.
"An investigation paper has been opened, and the case is being investigated under Section 8 of the National Anthem Act 1968 and Section 233 of the Communications and Multimedia Act 1988."
They also advised the public against issuing statements or spreading material on any platform to prevent speculation and provocation that could undermine the police investigation and threaten public peace.
Malaysia is a strong critic of Israeli policies and has no diplomatic ties with the Jewish state. It also bars Israeli passport holders from entering the country.