The Heroes actress died in August aged 36 and investigations have been ongoing into the circumstances surrounding her death in South Carolina.
Recent reports claimed the star had died after taking an oxycodone tablet laced with fentanyl.
However, the representative's statement urged fans not to believe everything they read, as they told People: "As reported yesterday by the Greenville County Coroner's Office, Hayden's death remains under investigation pending the completion of toxicology results, despite reports from some outlets stating otherwise.
"Recent reports attributed to unnamed sources are unverified hearsay and have attributed to conflicting information that continues to circulate.
"While we are all eager to find closure and better understand the circumstances surrounding her passing, we must remain patient and allow the investigative process to unfold."
They concluded: "The answers we are all seeking will come."
The statement came after multiple law enforcement sources with direct knowledge of the case told TMZ that Hayden had a "long-time drug dealer" in Los Angeles, who provided her with several black-market prescription medications.
She had allegedly taken a number of the medications with her on her flight from California the day before she died, with authorities reportedly working on the theory Panettiere took the oxycodone pill - believed to have been laced with the strong opiod - on August 16, the day of her death.
It was previously revealed that her on/off boyfriend Brian Hickerson had handed first responders a bag of her prescription medications when they arrived at the apartment they had been staying at when she died.
An autopsy previously found "no signs of trauma" that had contributed to the Heroes star's death.
A statement from Greenville County Coroner's Office read: "An autopsy was completed today. At autopsy no signs of trauma were discovered that would have contributed to the death.
"The cause and manner of death remain pending further investigation and the completion of additional studies. This investigation remains active and ongoing. No further details are available for release at this time."
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