DETROIT (WXYZ) - There are more questions as Detroit Police keep tracking the call that sparked a massive search along the riverfront.
Cops are now asking russian officials at the consulate to help with the case.
"While the search for a supposed Russian military officer has ended, the investigation is still far from over and it's still unknown who made that call to police."
From morning to night on Tuesday, cops, state troopers and feds combed Detroit's riverfront only to turn up empty handed.
An alleged russian military officer claiming he was kidnapped and stabbed in detroit seems more like a ghost now.
"If it was a prank it wasn't funny," says DPD spokesman Adam Madera.
"We could not afford to treat it as a prank. We had to put everything into it. We continued the investigation late into the night because we had to be sure we could not find this individual and covered every area we could cover," Madera said.
What police and federal authorities have now is a serious mystery. Police Chief James Craig ducked questions about the investigation but did offer this nugget about the 911 call.
"One thing I will tell you is that the number is a Russian phone number. We do know that," said craig.
Former FBI boss Andy Arena says it's possible someone was closely monitoring law enforcement as part of an elaborate hoax.
"It could have been someone probing law enforcement response, to see what resources they would bring to bear and how they would bring them to bear," says arena.
The name the man gave police still hasn't checked out.
A lot still doesn't add up, like there being no record of the guy even coming into the country.
"When a Russian military officer enters the United States that's a big deal. It's not just a regular civilian coming in for a vacation," says arena.
"So far, Detroit Police are not suggesting this was a hoax, but if in fact it turns out to be, you can expect criminal charges filed against the person responsible.