Ryan Zimmerman. (Thearon W. Henderson/Getty Images)

ATLANTA — A Major League Baseball investigation into allegations that Washington Nationals first baseman Ryan Zimmerman used performance-enhancing drugs found no violations of the league’s Joint Drug Prevention and Treatment Program, the Commissioner’s Office announced Friday. The league said both Zimmerman and Phillies first baseman Ryan Howard, who was also accused of PED use by pharmacist Charles Sly, cooperated fully with the investigation, though Sly did not provide any information.

Zimmerman and Howard were linked by Sly to the use of the banned hormone supplement Delta 2 in the Al Jazeera America documentary “The Dark Side” that aired last December on the now-defunct network. Howard and Zimmerman denied the allegations and filed separate lawsuits against the network and two of its reporters in January.

“I understand why Major League Baseball found it necessary to explore this matter, and I appreciate that MLB, after a thorough investigation, was able to publicly affirm my innocence,” Zimmerman said in a statement. “Throughout my life and career, I have been true to myself, my family, the Nationals organization and my community. It is not right that a so-called news organization and its personnel can publicly make false accusations that damage my reputation and call into question my integrity without any consequences whatsoever. 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.”

Defamation suits are notoriously hard to win, because not only must published information be proven to be false, but it must also be shown that the publisher knowingly published the false information.  Al Jazeera filed a motion to dismiss in April.

“Obviously, I’m one of the biggest advocates for drug testing and finding people who are cheating,” Zimmerman said. “MLB thoroughly went through and looked into everything me and [Ryan Howard] did and obviously cleared our name, but that’s we’re clear for the MLB side. But now it’s, the whole point of the lawsuit was to not allow people to basically smear your name without any evidence or without any proof. That [lawsuit] will go on.”

In the documentary, an undercover Al Jazeera reporter spoke with Sly, a former pharmaceutical intern who bragged about connections to such NFL stars as Peyton Manning and Clay Matthews, along with Howard and Zimmerman, to whom he said he provided performance-enhancing drugs. He claimed he had known Zimmerman for six years though Zimmerman later said they had never met. Sly later retracted his statements.

“Major League Baseball did a thorough investigation and came to the only conclusion supported by the facts,” said William Burck, attorney for both Howard and Zimmerman. “We believe Al Jazeera deliberately ignored the facts and relied on people they knew to be unreliable to report the story for its sensationalist value. Al Jazeera didn’t care about the truth or the harm they caused by broadcasting their false story.”

Zimmerman met with MLB representatives as part of the investigation, and was asked to provide documents and other information to investigators, he said. He opened himself up to similarly invasive discovery procedures by filing suit against Al Jazeera, something he said in February he hoped would show his determination to clear his name.

“From the beginning, I knew I didn’t do anything wrong,” Zimmerman said. “I think the people who know me the best knew that I didn’t do anything wrong. You’re always going to have people who are going to think what they want to think. But I think this further shows — I mean they went through and did their due diligence for seven months and couldn’t find anything. I guess there’s always going to be people who think what they want to think, but you can’t do anything about that.”

Friday’s announcement bolsters vehement claims Zimmerman made in a long and emotional meeting with members of the media when he arrived at spring training six months ago. Then, Zimmerman answered more than 30 minutes of questions about the accusations, some of which moved the normally stoic veteran nearly to tears as he described the effect the accusations had on his family and friends. Friday, he said he was mostly just happy to put the whole thing behind him.

“Obviously, [being cleared] is something that I expected,” Zimmerman said. “but just to have the whole situation done, we can move on to finishing the rest of the year, coming back and helping this team win for the last month and a half.”