Health officials in Qatar have announced they have found MERS or a MERS-like virus in three camels.
The camels were from a single farm where two men also contracted the virus.
The finding provides further evidence that camels can at the very least be infected with MERS or a very similar virus.
But it does not prove camels are driving the outbreak of the new coronavirus, which is a cousin of the virus that caused the 2003 SARS outbreak.
Recently officials from Saudi Arabia also reported a similar finding from a single camel in that country.
The World Health Organization has confirmed 160 infections with the new virus, all in or linked to six countries in the Middle East.
"This is our first clue which further fills out the whole story," says Bart Haagmans, a Dutch virologist who is involved in the effort to test the camel specimens.
"But there's more work to do, especially on routes of transmission."
Haagmans, who is with Erasmus Medical Centre in Rotterdam, says the team believes the findings are solid. They used three different tests, and found multiple fragments of viral RNA.
As well, the camels have developed antibodies to MERS, or a MERS-like virus, he says. Sequencing of that material is ongoing.
It has been reported that other types of animals were also present on the farm. Haagmans says testing of specimens from other animals is still underway.
While the working hypothesis is the virus originated in bats, scientists have been trying to figure out how people are becoming infected with it.
The assumption has been that one or perhaps several species of animals contracted the bat virus and are now spreading it among themselves and occasionally to humans.
A lot of attention has focused on camels. From time to time there have been reports that a person who became infected owned camels or attended camel races. But the WHO says many of the people who have contracted this virus reported no contact with the beasts.
Earlier this year European researchers reported finding antibodies to MERS or a similar virus in camels from Oman, the Canary Islands and Egypt.
But antibodies signal prior infection. To confirm that camels play a role in this story, science needs evidence of current infection.
Even with these findings, much of the puzzle remains to be completed. How are people contracting this virus? What puts them at risk? And what portion of cases involve animal-to-human spread at this point?
"For sure there is a part of the outbreak that is caused by human-to-human transmission," says Haagmans.
"The question is, what is the fraction of these cases? And how many independent introductions do you have through zoonotic" — from an animal —"transmission?"
The team involved in this work — from Qatar, the WHO and the Netherlands — is working on a scientific paper to lay out their findings.