Macaulay Culkin, who has been seen in photos this year looking completely gaunt, may have a heroin addiction, according to a friend who called the "Home Alone" actor's drug habit a "tragedy."

According to the National Enquirer, 31-year-old Culkin, famous for his roles as Kevin McCallister in the "Home Alone" series, is hooked on heroin and prescription painkiller oxycodone, which has caused him to lose a lot of weight over the last year or so.

"Macaulay Culkin is hooked on drugs, and it's killing him!" a source told the tabloid, adding Culkin had once even overdosed. "He's been hooked for a year and a half, and his drug of choice is either heroin or oxycodone. Mac is surrounding himself with junkies and lowlifes. It's a real tragedy."

However, Culkin's legal team denied the accusations that he has a heroin and drug addiction and axed the overdose rumor, Radar Online reported. The rep told TMZ the heroin rumor is "not only categorically without merit, but it is also impossibly and ridiculously fictitious."

"We beseech the responsible media to consider the source and its reputation and to please not perpetuate this destructive and insulting story by pursuing it any further," the publicist told TMZ.

The Enquirer report said that the former child star spends as much as $6,000 on drugs, which he keeps in his New York City apartment, called a "drug lair."

The source said the root of the problem has been his breakup with former girlfriend Mila Kunis, causing the actor to experiment regularly with drugs.

"Macaulay Culkin is surely dying," another source told the Enquirer. "He's addicted to heroin, oxycodone, Percocet and Vicodin. I have witnessed his drug taking, which has escalated over the past year and a half to the point where he needs serious help."

The second source added that his physical condition is alarming, which has many worried about Culkin's life.

"His closest friends fear that he'll overdose or his heart will explode. If he doesn't get help and enter rehab now, he could be dead in six months," the source said. "It should have been a wake-up call, but it didn't seem to have any effect on him. Mac is still partying hard. I pray that he finds the courage and strength to clean up before it's too late."

Back in February, Culkin was seen in photos from "Entertainment Tonight" after cancelling an impromptu gig as a disc jockey in New York City looking more than just "skinny" or "thin," but terrifyingly gaunt. An eyewitness said Culkin looked "super skinny" and "emaciated" wearing jeans and sneakers while holding Natalie Portman's then eight-month-old son, Aleph.

The photos prompted Culkin's rep to defend the "Home Alone" star.

"Macaulay Culkin is in perfectly good health," Culkin's rep told E! News. "For Entertainment Tonight, or any other media outlet, to speculate otherwise is reckless, irresponsible and destructive. We implore them to discontinue the rumor."

According to Entertainment Weekly, which posted the original photos of the gaunt actor, Macaulay Culkin was slated to star in a film in the UK, "Service Man," set for a 2013 release. However, the project is not credited on the actor's IMDb page.

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