That is not confirmed as yet. It appears that a family member received a phone call from someone reporting that the miners were found alive. Who was on the other end of the phone and where did they get their information from is the question.
Some reports state that it was someone on the inside, telling family members. Other reports claim it was a relative calling to report what they heard on the news.
What other reports? That's the first I've heard of that.
There has been a lot of criticism directed at the media, the governor, and the company officials on this thread. At this point in time, I'm inclined to believe that the original source of the incorrect information was just some moron with a cell phone who was somehow involved in the search/rescue operation.