Jean Batista, who is having a great start in Greeneville this year was signed in 2010 for a reported $300,000. He was initially reported as a 17 year old when his signing was released in May. As is usual in the Domincan Repubic, the signing was subject to verification by MLB. He didn't show up on the DSL roster in 2010 and then played for the GCL & Greeneville in 2011 as a 19 year old.
The Astros media guide list his signing as November 15, 2010 which happens to also have been his 19th birthday, according to the date of birth listed in the media guide.
During the time of his signing, Jean Batista was being followed by camera crew filming the documentary "Pelotero". The web site for the documentary hints that there were problems about the age in the character summary of Jean Carlos Batista. But I had not heard anything definative on the subject until today.
Pelotero Trailer [US Theatrical Premiere at the Maysles Cinema, July 13th - 19th] from Maysles Cinema on Vimeo.
The documentary's executive producer is Bobby Valentine. He was interviewed on WEEI about the documentary in conjunction with the July 2nd international signing day. In talking about the pressure on Dominican youth to falsify their age, the interview recaps Batista's situation. He talks about how the age issue may have been unintentional but that it changed his status as prospect dramatically; it changes his signing bonus dramatically and it changes how he is perceived by the Houston organization dramatically. The section about Batista can be found at the 8 minute 50 second mark in the pod cast, I have paraphrased the comments but there is much more there.
So this answers some questions about his age but it doesn't change the fact that Batista is a 20 year old hitting the ball very well in the Appy League right now. The documentary will be released in limited theaters and on itunes on July 13th.