Despite the union's clearance, MLB will continue to look into the Melky Cabrera controversy. (US Presswire)

MLB powers are continuing to investigate the leadership of the powerful Brooklyn-based ACES, which has been found liable by the players' union for employing or contracting with a rogue agent but cleared by the union of the more serious allegation of perpetrating or aiding the fraudulent scheme to cast doubt on ACES client Melky Cabrera's failed drug test.

MLB bigwigs have seemed much more skeptical than the union of the entire ACES operation from the time MLB uncovered the scam. The union has now officially accepted the explanation by ACES chiefs Seth and Sam Levinson that their rogue worker Juan Nunez paid for and engineered the internet scheme intended to show Cabrera accidentally acquired a tainted substance.

If MLB finds more serious wrongdoing, it could contest the union findings. Union people have suggested agent behavior comes under their purview alone, but MLB may not easily accept a wrist slap if it finds evidence to more closely tie the Levinsons to the scheme.

Cabrera was banned 50 games for failing a test for synthetic testosterone after a case to nullify the banned test  was made by the union at the behest of the Levinsons, who claimed then that Cabrera accidentally acquired the banned substance after answering an internet ad for a supplement. The Levinsons have since claimed that they were merely taking the word of Nunez, a longtime employee or contractor. Nunez testified he perpetrated the hoax on his own, not at the behest of the Levinsons, who declined to call Nunez an employee even though he has worked closely with the Levinsons for years and is responsible for funneling many millions of dollars to them in the form of major-league clients over many years.

MLB has been in touch with federal investigator Jeff Novitzky and appears to be taking its investigation very seriously. MLB honchos interviewed former catcher and Levinson client Paul Lo Duca, who testified the Levinsons set him to acquire PEDs from baseball drug dealer Kirk Radomski.

Former baseball drug czar George Mitchell never mentioned the Levinsons in his report, and MLB people seem to believe the Cabrera caper is the more vital area to investigate. The union also apparently either found no evidence regarding a Radomski/Levinsons connection or declined to investigate it.

Four clients have left the Levinsons in recent months, Shane Victorino, Everth Cabrera, Johnny Gomes and Nyjer Morgan, though it's been suggested Victorino didn't leave due to the allegations or investigation. Dustin Pedroia and other clients have considered leaving, as well, but so far the exodus appears limited to the quartet.