MLB's new investigative unit, based in New York, will look into 42-44 players, including several top prospects, who signed all types of bonuses, Melendez said. Players who are found to have used false information in their applications may be in danger of having their visas revoked or suspended.
Under the previous administration at the consulate, the report said, players only had to prove their identities to secure visas, even if MLB investigators in the Dominican Republic had any questions regarding age.
"The previous administration didn't care if [players] were 17-18," Melendez said. "These guys do. ... Of course it's troubling because some of these cases are two to three years old. Some of these guys have traveled to the United States already."
Dominican U.S. Embassy spokesman David Searby could not be reached for comment, the report said.
Last month, the same MLB investigators based in New York found that a Washington Nationals prospect known as Esmailyn Gonzalez had falsified his age and identity. Instead of being 19, as he said, it was determined that he was 23-year-old Carlos Alvarez David Lugo.
The Nationals thought that Lugo was 16 years old when they gave him a $1.4 million signing bonus in 2006. Lugo has not been able to secure a visa to travel to the U.S. and join the team in Spring Training, his agent said on Monday.
All of the players previously investigated were awarded visas, regardless of whether their cases were flagged for potential age irregularities.
"Our investigations reflected [the age issues]," Melendez said of MLB's Dominican office.
Bobbie Dittmeier is an editor/producer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.