Joe Biden's presidential campaign is accusing President Trump's campaign of poaching online donors. In a fundraising email sent to supporters Thursday, the Biden campaign pointed out that if someone types "donate Joe Biden" into a Google search, the first link to appear is one that directs them to donate to Donald J. Trump for President.

Here's what the search turned up Friday morning:

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"Trump's campaign is paying money to run ads online so that their donation link is the first thing you see when you search 'donate Joe Biden,'" the email read. "But, listen, here's the thing: We can't stop them because we're out of money to run online ads for the rest of the month."

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While the Biden campaign is calling out President Trump's reelection campaign, it's not immediately clear who exactly is behind the ad making the Trump campaign page appear above Biden's in the search. The Trump campaign has not yet confirmed that it purchased the Google ad, which was purchased on Google's pay-per-click keyword advertising platform.

The Trump campaign ad appears after a search of the specific words, "donate Joe Biden," in that order. It doesn't come up if users type "Joe Biden donate" or "donate Biden" in the search field. It's also unclear whether these efforts have affected the attempts by Biden supporters to donate to the former vice president's campaign.

Because there is a host of requirements for advertisers running Google ads that mention political candidates, it seems likely that the Trump campaign is responsible for the digital ad, according to Bully Pulpit Interactive, a digital marketing and strategy firm.

"The interesting part of the Trump ad strategy to me is that, even though the ads click through to a Trump campaign donation page, they are probably not driving many donations. People searching 'donate to Biden' are Democrats who have already made up their mind on who they are supporting and how," J.D. Bryant, Bully Pulpit's director of buying, told CBS News.

He went on to say, "They are really unlikely to suddenly change their minds and switch not only the candidate but also the party to which they are giving money. That means the people behind this ad aren't doing it because it's a smart digital tactic. They're doing it because they'll do anything to keep the attention on Trump."

In the second quarter of the year, Biden raked in more than $22 million putting him just behind Pete Buttigieg in fundraising in that period. However, his fundraising efforts are not the same type of grassroots operations as those deployed by Bernie Sanders or Elizabeth Warren, who have both sworn off big-dollar fundraising events. The president and his campaign committees raised $54 million in the second quarter.

A Google search of other top polling Democratic presidential candidates in the race, including Sanders, Kamala Harris, Warren and Buttigieg, found no other candidate faced the same type of targeting when searched online.

This is not the first time the former vice president and current Democratic presidential frontrunner has been an online target. An search of "Joe Biden" lists a parody account just below his official website on Google. The website includes references to "Uncle Joe," old videos and images of Biden awkwardly touching women, and a series of policy positions far outside the norms for progressive Democrats. The New York Times previously reported the website had been created by a Trump consultant.

Dan Patterson contributed to this report.