(Cover) - EN Showbiz - An autopsy on Ryan Dunn is being carried out to determine if alcohol played a part in his death.

The 34-year-old Jackass star and a male passenger were killed in a car crash in the early hours of Monday morning in Pennsylvania. There have been conflicting reports about Ryan's final hours after he posted a photograph of himself drinking with pals in Barnaby's bar on Sunday night. TMZ has reported that Ryan had six alcoholic drinks including beer and shots - before he got behind the wheel. One source who was at the same bar as Ryan has alleged the star was "wasted", but another reveller insisted he wasn't "too drunk to drive".

One of the bar staff has also come forward to say Ryan "didn't seem intoxicated".

"He was himself," the Barnaby's employee told MTV News. "He seemed like he was having a good time, hanging out with his friends."

An official police report explains that a "preliminary investigation revealed that speed may have been a contributing factor to the accident".

An autopsy is also being conducted on Ryan's as-yet unidentified passenger, according to TMZ.

It is not yet known when the toxicology results will be released.

Ryan's close friend and Jackass co-star Steve-O has spoken about his grief. The star revealed he was lost for words after hearing about the fatal car accident.

"I don't know what to say, except I love Ryan Dunn and I'm really going to miss him," Steve-O said on his Twitter account. (C) Cover Media