(The Sports Xchange) - Philadelphia Phillies first baseman Ryan Howard and Washington Nationals first baseman Ryan Zimmerman were cleared of wrongdoing in Major League Baseball's investigation into their possible use of performance-enhancing drugs, prompted by an Al Jazeera report.

MLB announced Friday that the investigation was complete and it "did not find any violations of the Joint Drug Prevention and Treatment Program by either Howard or Zimmerman."

The Al Jazeera report, aired in a December documentary, claimed that Howard and Zimmerman were among the athletes who allegedly received shipments of performance-enhancing drugs.

The report was based on recordings with Charles Sly, a former worker at the Guyer Institute in Indianapolis. Sly also implicated several NFL players, including Peyton Manning.

Slay has since recanted his statements. He also declined to speak with the commissioner's office or provide requested information.

Howard and Zimmerman filed lawsuits against Al Jazeera in January. The players claimed the report was inaccurate, unsubstantiated and reckless.

"I look forward to holding the responsible people accountable for these false and defamatory claims in my ongoing litigation against Al Jazeera and its reporters," Howard said in a statement after the announcement.

Zimmerman echoed Howard's comments and says he also plans to continue his litigation.

"As I said in January when I filed my lawsuit, I am determined to hold Al Jazeera and its reporters accountable for their defamatory actions."

(Editing by Andrew Both)