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WASHINGTON — An email that was sent to then-candidate Donald Trump and his son Donald Trump Jr. in Sept. 2016 pointed them to hacked WikiLeaks documents that had already been made public, according to a copy of the email provided by Trump Jr.'s lawyer.

The email, first reported by CNN, offered a decryption key and a website address to access the documents, the officials said.

But the email is dated Sept 14, not Sept 4, as CNN had reported. On Sept 13, the day before the email, WikiLeaks had tweeted links to what the group said was 678.4 megabytes of DNC documents.

The email was from a Yahoo address with the name of Michael Erickson, and the writer described himself as the president of an aviation management company. A person who appeared to be Erickson did not respond to requests for comment by NBC News.

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Trump Jr.'s attorney, Alan S. Futerfas, said in a statement to NBC News that the email "arrived after published media reports disclosed 12 hours earlier that hacked documents had been posted. The suggestion that this information was not public is false. The writer is unknown to us. The email was never read or responded to – and the House Intelligence Committee knows this."

Futerfas said Trump Jr. was questioned about the matter Wednesday during his interview with the House Intelligence Committee.

It's not clear what this has to do with @WikiLeaks. Many enthusiastic readers emailed around archives of our publications during the election. https://t.co/HMRYWgCsvB — Julian Assange (@JulianAssange) December 8, 2017

"It is profoundly disappointing that members of the House Intelligence Committee would deliberately leak a document, with the misleading suggestion that the information was not public, when they know that there is not a scintilla of evidence that Mr. Trump Jr. read or responded to the email," he said.

In addition to Trump Jr., the email was sent to a campaign address for Donald Trump, as well as Trump Organization attorney Michael Cohen. Its subject line said: "Trump: Another WikiLeaks DNC Upload."

"It is too big to send to you by email attachments," the email said, but instructed the Trump team where to download the material.

At the time, it was widely known that the Russians had hacked Democratic emails, and it was strongly suspected they had turned them over to WikiLeaks. Candidate Trump was praising WikiLeaks repeatedly.

WikiLeaks founder Julian Assange, in a tweet, distanced himself from the email, saying many readers had circulated archives of the site's publications.

Last month, Donald Trump Jr. released a series of direct messages he received from the Twitter account behind the WikiLeaks website, including his responses to the communications.

The messages, which began in September 2016 and ran through July, show Trump agreeing to "ask around" about a political action committee WikiLeaks had mentioned and asking the site about a rumor about an upcoming leak.

The messages were turned over to congressional committees investigating Russian intervention in the 2016 election and if there were any links to Trump's campaign.