Johor Police Chief Wan Ahmad Najmuddin Mohd said the party had just started when police, acting on a tip-off, raided several rooms in the apartment.
The two-hour operation began at 2am.
“Thirty-five males, including four boys, and 10 females, including four girls, tested positive for drugs,” he said.
They were aged between 14 and 26.
He advised parents to monitor their children to prevent them from being entrapped in immoral and drug activities.