They referenced buying drugs and his battle with his "demons".
"It's stream of consciousness and difficult to follow," one source said. "In one line he refers to 'Frank who always owes money' and on the same page he writes about a 15-year-old girl from Texas."
Another source told NBC: "It seems he did at least part of it in rehab. It definitely contained some soul-searching. But there is also a fair amount of rambling that doesn't make sense."
Hoffman entered rehab for at least 10 days in 2013, admitting that his use of prescription drugs had escalated to heroin.
News of the diaries comes after a drug dealer charged in connection with the beloved character actor's tragic death claimed he could have saved his life.
In a jailhouse interview on Rikers Island, Robert Vineberg, a jazz musician and fellow junkie, denied selling Hoffman the drugs that killed him, insisting he hadn't seen the star since October or even heard from him since December.
"I could've saved him," Vineberg told The New York Post. "If I knew he was in town, I would've said, 'Hey, let's make an AA meeting.' If I was with him, it wouldn't have happened. Not under my guard."
Vineberg said he had known Hoffman for about a year and the pair were friends, getting together to talk about books and art.
"He was a normal guy. You wouldn't know he was an Oscar winner," he said.
But he said the actor was a "hardcore addict" with a 10 bag-a-day heroin habit.
The performer, who has worked with Madonna, Wyclef Jean and the late Amy Winehouse, said he last saw Hoffman in October, when the actor was high at his Mott Street apartment, where police arrested him last week.
After that, things seemed to be looking up for the actor.
He went on a 28-day rehab stint before flying to Atlanta to shoot the upcoming Hunger Games movie.
"He left me a voicemail in December saying, 'I'm clean'," he said of their final contact.
Hoffman was found dead in his bathroom a week ago with 73 bags of heroin scattered around his West Village apartment. He still had a syringe in his arm, it was reported.
But Vineberg, 57, denied supplying him with the drugs that killed him. When The Post asked if he had ever sold Hoffman drugs, he refused to answer.
He said he was "devastated" by Hoffman's death and offered his condolences to his family.
He suggested his brief stint off the drugs may have made him more susceptible to overdose.
"When you're clean for that long of a time, your body can't take as much," Vineberg said. "Your body doesn't have the tolerance."
He added: "He was a hard-core addict."
He is convinced that Hoffman was injecting 10 bags a day.
"How much was he found with? Seventy bags. You do the math ... That's a one-week supply," he said.
NYPD sources told the Post the estimate - about twice that of an average junkie - was about right.
Vineberg was also a drug user and the pair battled with their addiction together, he said.
Vineberg managed to stay clean for a week at a time between relapses and said he and Hoffman would text back and forth, to keep one another on the straight and narrow.
But they fell out of touch late last year.
Vineberg was charged with felony drug possession and was one of three people dealers charged in connection with Hoffman's death. A young couple who lived nextdoor to Vineberg's Mott Street apartment, where cops seized some 300 bags of heroin, were charged with misdemeanor cocaine possession.
Wearing a gray prison jumpsuit, Vineberg told The Post he's "a scapegoat" in the case.
His attorney insists there is no evidence to suggest Vineberg supplied Hoffman with the deadly narcotics and claims the pair "were true friends who had bonded over and struggled with the dangerous use of narcotic drugs".
- The Daily Mail
