Famous American magician Criss Angel has vowed to raise $5 million for cancer research after his five-year-old son's leukemia returned.

The superstar illusionist's son Johnny Crisstopher was first diagnosed with cancer back in 2015 at just 21-months-old, prompting Criss to make a documentary about his son's chemotherapy treatments, and raise $1 million for paediatric cancer research, reports aceshowbiz.com.

Angel tells tmz.com that despite three years of treatment that eventually brought him into remission, Johnny Crisstopher has had a "relapse" and will be admitted to hospital on December 09.

Before then the star plans to take him on special trips to Disneyland and Universal Studios in a bid to keep the youngster's spirits up.

The magician went on to say that he plans to host a special charity event at Las Vegas' Planet Hollywood resort, the home of his regular "Mindfreak" show.

He says he'll be roping in "dear friends" and "huge artists" for the one-off show next year, but that he needed the public's help to reach his ambitious $5 million fundraising target.