Days after multiple reports surfaced claiming that former Disney star Zac Efron had attended rehab to battle an alleged addiction to cocaine, friends of the actor are stepping forward to discuss his substance abuse problems.

An "insider" close to the 25-year-old former “High School Musical” star told Radar Online Thursday that those close to the actor are fearful he will relapse or overdose similar to the way “Glee” star Cory Monteith passed away at the age of 31 in July from a heroin and alcohol OD. “Friends are genuinely worried about him,” said a source. “Because if Zac relapses like Cory Monteith did, he’ll likely go back to using the same amount of drugs he was doing before rehab.”

The report claims that Efron has been in a “downward spiral” since 2011, the same year he was shooting the Garry Marshall dramedy "New Year’s Eve" alongside Michelle Pfeiffer.

“He was just good at hiding, it not getting caught,” said a source, claiming the actor began dabbling in drugs because he wasn’t satisfied with his life. “He was partying because he was unhappy and basically just didn’t give a f—k,” the insider added.

While some have reported Efron’s friends' concerns, another source told Us Weekly Wednesday that the former Disney star is in a “good place" while working on his latest film, "Autobahn."

“He realized he needed outside help," an unidentified friend told the magazine. "He reached out for it and is doing great now.”

Reports of concern from Efron’s friends comes one day after People magazine reported that the California native had attended a rehab program five months ago to treat a substance abuse problem. TMZ later reported that the actor was treated for a “serious cocaine addiction.”

"It was common knowledge he was struggling with cocaine,” said a source, claiming Efron was frequently a no-show on the set of the upcoming comedy “Neighbors” and dabbled in taking “Molly,” a form of Ecstasy.