According to authorities, the man and woman were Vietnamese tourists and were part of a group that came out from the L.A. area.
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Officials say a welfare check of the room was done at about 3 p.m. Friday after the couple didn't show up for a tour of the Grand Canyon. That's when police discovered the couple both dead of multiple stab wounds.
"We're early on in the investigation and at this time we have not been able to determine if it's a murder-suicide or if it's a double homicide investigation," Las Vegas Metropolitan Police Department Lt. Ray Spencer said at a press conference. "So we do not know at this point."
Spencer says police are "leaning" toward the incident being a murder-suicide, but that they won't know for sure until the coroner's examination.
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Witnesses also reported hearing a disturbance that sounded like an argument near the area around 2 a.m.
No suspect information was provided. Authorities said that the incident was isolated.
The investigation is ongoing.
ABC News and KABC-TV contributed to this report.