The variant, named B.1.617, was detected in an Indian national screened at the Kuala Lumpur International Airport, he said.
The World Health Organisation has described it as a "variant of interest", suggesting it may have mutations that would make the virus more transmissible, cause more severe disease or evade vaccine immunity.
"We advise the public to remain calm... All public health efforts will continue in order to break the chain of infection and ensure public safety," Adham said.
He did not say when the variant was detected.
Malaysia, which is facing a surge in COVID-19 cases, on Wednesday banned flights to and from India and prohibited travellers from any Indian destination from entering the country to prevent the spread of the new variant.
India is battling a devastating second wave of the coronavirus that has overwhelmed hospitals, morgues and crematoriums.
Malaysia in February launched a nationwide COVID-19 vaccination programme, aiming to inoculate 80% of its 32 million people within a year.
The Southeast Asian country reported 3,418 new coronavirus cases on Sunday, bringing its total number of infections to 415,012 cases, including more than 1,500 deaths.
