Andrew Embiricos in 2008
12/07/2011 at 01:00 PM EST
Though reports claim the death of Rita Hayworth's grandson appears to be a suicide, a friend of Andrew Embiricos does not believe he killed himself.
"The reports are not true," Jake Dingler tells PEOPLE of speculation his friend – who was found dead
Sunday in his New York City apartment in bed with a plastic bag over his head – committed suicide.
"I spent the last eight hours of his life with him and he was very happy and looking forward to all of the events coming up," Dingler says. "We were going to Amsterdam on Friday for his 26th birthday. We were having brunch with his mother the following morning and we had a lot of great things to look forward to."
Meanwhile, a spokesperson for the Medical Examiner's office tells PEOPLE, "the cause of death is still under investigation and pending further tests," which could take weeks.
One thing is for sure: family and friends, who are reportedly shocked by Embiricos's death, are devastated.
"He was the most charismatic person and outgoing and fun and actually the best friend you could have ever asked for," Dingler said of the '40s film star's grandson, who was 25. "I will miss him for the rest of my life."
Additional reporting by LIZ MCNEIL