Washington(CNN) President Donald Trump on Tuesday night made an eyebrow-raising claim on Twitter: The FBI's investigation into the Trump campaign began in December 2015, he said -- not July 2016, as former FBI Director James Comey had testified under oath.

"SPYGATE is in full force!" Trump exclaimed, citing text messages between the FBI officials Peter Strzok and Lisa Page. "Is the Mainstream Media interested yet? Big Stuff!"

But a CNN review of the text messages between Strzok and Page show no evidence to back up Trump's claims that the Trump-Russia investigation started in December 2015. And it appears that Trump was relying on a Fox Business host who suggested there were new, unredacted text messages. But those texts had actually been sitting on a Senate committee website for four months.

Trump tweeted roughly an hour after Fox Business' Lou Dobbs claimed on air that "the FBI May have initiated a number of spies into the Trump campaign as early as December of 2015."

That report came after the far-right website Gateway Pundit seized on a Twitter user and a Reddit forum posting the texts on Monday to claim the FBI was running spies into the Trump campaign in December 2015.

The revelation shines a light on how Trump tends to seize on conspiracy theories to further his arguments, blasting out unsubstantiated charges on Twitter to try to torpedo special counsel Robert Mueller's investigation into possible collusion between the Trump campaign and Russia. On Wednesday, two top Republicans -- House Speaker Paul Ryan and Senate Intelligence Chairman Richard Burr -- said the FBI acted appropriately in how it interacted with a confidential FBI source who was in contact with several campaign aides, breaking with Trump's claims of spies implanted in his campaign.

The latest conspiracy theory appears to have no basis in reality.

The text messages in question are an exchange between Strzok and former FBI lawyer Page, who traded thousands of texts while having an extramarital affair and whose messages have been seized on by critics to argue Mueller's investigation is biased against Trump.

In December 2015, Strzok texted Page: "You get all our oconus lures approved? ;)"

"No, it's just implicated a much bigger policy issue. I'll explain later. Might even be able to use it as a pretext for a call... :)" Page responded.

In the texts, "oconus" refers to "outside the continental United States," while Trump-friendly media who have suggested the investigation started in December 2015 claim that "lures" is FBI shorthand for spies.

Lures is a word in FBI parlance, but it's not a reference to spies -- it means enticing a "criminal defendant to leave a foreign country" so they can be arrested and prosecuted in the US, according to Justice Department regulations.

Regardless, none of the text messages from that same time period in December 2015 discuss any kind of investigation into Trump or Russia, although in one text Page shared a news article about Trump and called him "an utter idiot." The pair texted multiple times a day about many things including work matters, promotions and news coverage of all kinds of topics.

Congressional sources from both parties who have reviewed the texts say they have no reason to believe the text is referring to a counter-intelligence investigation into the Trump campaign.

And at the time the text messages were sent, none of the people the FBI was probing in its counterintelligence investigation -- Paul Manafort, George Papadopoulos, Carter Page and Michael Flynn -- had even joined the Trump campaign yet.

The texts were included in hundreds of pages of text messages released in February by Republicans on the Senate Homeland Security and Government Affairs Committee. The text exchange at the center of the conspiracy theory was listed in the 500 pages of documents twice, once with "lures" redacted and once unredacted.

But the committee made no mention of the text exchange in question in its interim report detailing FBI actions in 2016, a sign that it did not view the message as significant.

Congressional sources said that the likely reason the text was both redacted and unredacted was that the Justice Department sent over multiple document productions in a hasty and chaotic manner.

Wisconsin Sen. Ron Johnson, the Republican chairman of the committee, told CNN he wasn't familiar with the texts the President had referenced, adding he was focused on the upcoming inspector general report on the FBI's actions in 2016 and getting more information from the Justice Department.

"I don't have a catalog of all the texts," Johnson said.

On Monday, the chain of events leading to Trump's tweet kicked off when a Twitter user took a photo of the two texts and claimed they showed the FBI was "using foreign agents against Trump."

After a Reddit forum picked up the image, the far-right website Gateway Pundit published a story Monday running with the conspiracy theory.

No news organizations wrote about the texts until Tuesday evening, when Dobbs ran a segment on Fox Business in which he claimed that the FBI "may have initiated a number of spies into the Trump campaign as early as December of 2015."

Dobbs' guest, Judicial Watch's Chris Farrell, agreed with Dobbs' unproven claims. "From very early on back in 2015, there's a concerted effort by agents from the FBI to apply intelligence tradecraft and intelligence operations to attack and undermine candidate Trump and now President Trump," Farrell said.

Less than an hour after Dobbs' show wrapped, Trump sent his tweet claiming the FBI's counter-intelligence campaign dated back to December 2015. In a subsequent tweet, Trump touted the "great interview" by Dobbs.

Trump's tweet put the issue on the radar of Fox News. With an on-screen banner claiming "New Strzok-Page texts released," Fox News host Laura Ingraham claimed, "It certainly appears they were looking to put more lures into the campaign in 2015."

Rep. Ron DeSantis, a Florida Republican who has been a sharp Mueller critic, did not dispute Ingraham's contention on her show, raising questions about why the text had been redacted.

"This did not just start in the 31st of July (2016)," DeSantis said of the FBI's investigation.

DeSantis spokeswoman Elizabeth Dillon said DeSantis believes investigative activity occurred on the Trump-Russia case before July 31, 2016, but he hasn't made a judgment about the December 2015 texts. A White House spokesman did not respond to a request for comment.