NEW YORK — It was the summer of 2009, and Cameron Douglas was strung out on heroin — again.

Holed up in a trendy Manhattan hotel, the wayward heir to Hollywood royalty — son of Michael, grandson of Kirk — was shooting up sometimes six times a day.

His own stabs at stardom had mostly gone nowhere. But notoriety found him when federal agents showed up at his hotel door to cast him in an unwanted role: methamphetamine trafficker.

"I must admit that my immediate reaction when I learned of my son's crime was one of guilt," his mother, Diandra Douglas, wrote in one of several letters from supporters asking a federal judge for leniency at a sentencing scheduled for next week.

Said actress Catherine Zeta-Jones, married to Michael Douglas: "My stepson is a caring, considerate, worthy human being, but nevertheless the disease that he has for years tried to combat did take over again."