Macaulay Culkin
Macaulay Culkin, 31, a former child star, was photographed in New York this week looking extremely thin and old. A rep for the actor has told the media that he is in good health. Twitpic

Macaulay Culkin was spotted at Natalie Portman's wedding on Saturday in the wake of unconfirmed reports that he had fallen into deep heroin addiction and rumors of his death circulating on the Internet.

The actor was among the roughly 100 guests on hand at a private residence to witness Portman tie the knot with Benjamin Millepied, according to Us Weekly.

A source told Us Weekly that Culkin and Portman, both 31, have been friends for a long time. Portman starred alongside Culkin's ex-girlfriend Mila Kunis in the 2010 film "Black Swan." After an eight-year relationship, and a rumored engagement, Culkin and Kunis split up early last year.

During a Parade interview in 2007, Kunis made some statements about Culkin that, in hindsight, could be meaningful considering the latest gossip surrounding the "Home Alone" star.

"There are a lot of things people want him to be that he's not," Kunis said. "He's an amazing, simple guy, who is probably the most brilliant person I've ever met. He's so, so smart and so aware and so kind and so sweet. Unfortunately, that's not what people want him to be, so they write stuff."

After years out of the public eye, Culkin has been blogosphere and tabloid fodder since the National Enquirer reported Friday the actor had only six months to live because of his drug habit. The unsubstantiated story quickly went viral and had fans worried that Culkin really was spending as much as $6,000 a month on heroin and highly addictive painkillers such as oxycodone. A representative of Culkin told TMZ the allegations were "not only without merit, but ... also impossibly and ridiculously fictitious."

The Enquirer responded to those claims by challenging Culkin to take a drug test.

"Our advice to Macauly is to seek professional help to avoid the same tragic fate of other beloved celebrities," the Enquirer wrote before referring to Culkin's friend, Elijah Rosello, who died of a drug overdose. "We believe that the former child star should be doing everything he can to get the treatment he so desperately needs -- and which could have saved the life of his friend Elijah Rosello."

Culkin's half-sister died in 2000 of a drug overdose, reported the Daily Mail, which also said Culkin was arrested in 2004 on suspicion of having marijuana and two controlled substances.

The reclusive actor rose to fame in the 1990s for his portrayal of Kevin McAllister in "Home Alone and "Home Alone 2: Lost in New York." In those hugely successful movies, Culkin played a character who outwitted burglars after being left behind while his family went on vacation. He also appeared in "Richie Rich," "Uncle Buck," and "Saved!"