(Pinal County Sheriff's Office/AP Photo)

Five bodies found in a burned SUV in the Arizona desert are likely a Tempe family who went missing after  the father sent a co-worker a cryptic note about how to take over the family business, police said today.

The sheriff in Pinal County, where the burned out SUV was found, initially said all signs indicated that it was likely related to Mexican drug cartel trafficking, but investigators have since learned that the white Ford SUV was registered to the business of James Butwin, at the family's home address.

The coroner has not yet make a positive identification, but the fact that there were five bodies and all five members of the Butwin family have been missing since Saturday, along with evidence gathered at the family home, led police to suspect that they were  the two parents and three children, Tempe Police Department Sgt. Jeff Glover said.

"From the evidence that our detectives were able to gather from the residence, they believe it is a murder-suicide," Glover said.

Tempe police were not initially involved, since the bodies were found in Vekol Valley, a desert area in Pinal County that's a well-known smuggling corridor for drugs and illegal immigrants from Mexico, but they contacted officials there after learning of the mysterious disappearance of the Butwin family, he said.

"It was a situation where a family acquaintance received a note or letter from James Butwin [the father] that indicated how to run the business, which caused concern," Glover said. "They went over to the residence and couldn't  find anyone, and that's when they called police."

Glover identified the missing family only as James Butwin, his wife Yafit Butwin, and three children. He said he did not have specific ages for any of the family members, and said the children's names were not being released.