Assistant Chief Coroner Ed Winter tells ET that there were pills located next to White when her body was found, and the note that was also retrieved at the scene includes Carrey's name. Winter says he has not seen the letter, and therefore, is not certain if the letter was addressed to the 53-year-old actor.
An autopsy has not been conducted yet, according to Winter, and toxicology reports typically take eight to 10 weeks to determine the official cause of death.
Meanwhile, White's family released a statement to The Irish Independent, calling the 30-year-old a "beloved daughter and sister."
"Cathriona was a shining light in our lives who was loved deeply by her entire family," the statement reads. "We will miss her terribly and at this difficult time we ask to be left in private to mourn our loss."
On Monday night, White was found unresponsive at her Sherman Oaks, California, residence. She was pronounced dead at the scene.
Carrey met White in 2012 and the two dated on and off for the last few years.
"She was a truly kind and delicate Irish flower, too sensitive for this soil," the actor said in a statement to ET. "My heart goes out to her family and friends and to everyone who loved and cared about her."
If your or someone you know needs help, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).