(CNN) — Texas Gov. Greg Abbott boasted shortly after he began soliciting private donations for his controversial migrant busing program that there would likely “be no cost to the state” given the outpouring of support from concerned citizens across the country.

But after nearly two years of fundraising to offset the program’s costs, Abbott’s operation has collected less than half of 1% of the roughly $150 million spent on busing migrants to sanctuary cities, according to a review of state records. And CNN found that the largest donation – $900,000 – never made it into the state’s coffers, either because it was a mistake or a prank.

Records show that at most, around $550,000 has been raised to date.

The data provided by the state reflected donations submitted online or by mail through check, credit card or bank transfer, not funds actually received by the state — meaning the data could contain donations that were rejected by banks and credit companies during processing. Reporters tried to reach the woman behind the supposed $900,000 donation, but they could not locate the person with the name provided, and the phone number submitted to state officials was disconnected.

Abbott’s office published a running tally online to show how willing people were to support his program. After the $900,000 contribution was submitted online in September, the website showed that donations had reached more than $1.3 million, but in December, the tally was readjusted – dropping back down to around $460,000.

CNN also spoke with another donor listed in the data who confirmed he did not make the $2,000 donation listed under his name. Yet another donor showed reporters a letter he said he received from the state after complaining that his $1,000 donation to the state border wall fund had been instead allocated to the busing efforts.

The governor’s office did not respond to CNN’s questions about the mystery donation, other discrepancies and whether any of the other donations listed in the state data did not come through.

Since the busing program started, Texas taxpayers have largely footed the bill. The governor’s office says it has transported more than 100,000 migrants from Texas to sanctuary cities around the nation, including New York City, Chicago, Washington, DC and Denver. Given the payments made to private contractors so far as detailed in public records, this means it has cost about $1,500 to move each migrant out of the state.

Immigration advocates have slammed this operation as a dangerous and inhumane publicity stunt, and sanctuary city mayors have also fought back against Abbott’s program, instituting regulations about when and where the buses can drop off migrants, as the cities have struggled to meet the needs of the sudden influx of asylum seekers. Last year, a 3-year-old migrant girl died while on a bus to Chicago as part of Abbott’s busing program, and a 10-year-old girl was reportedly hospitalized the prior year due to dehydration and a high fever while on a bus to Philadelphia.

Securing the border has been a hot button issue as the presidential election nears. While many Republicans have lambasted President Joe Biden for not doing enough to stop migrants from crossing the border, some immigration advocates and attorneys say he has actually made it too difficult for migrants to go through the legal process to seek asylum in the country.

Aside from the unfulfilled $900,000 contribution, the largest donation in the records came just last month from Wyoming megadonor Timothy Mellon, an heir to the Mellon family fortune. Mellon donated $50,000 to the busing program, far less than the tens of millions of dollars that the Texas Tribune reported he contributed to the state’s border wall fund. He has also donated millions to Super PACs supporting presidential candidates Donald Trump and Robert F. Kennedy Jr. this year alone, according to Federal Election Commission filings. He did not respond to a request for comment.

CNN reached some of the donors on the list who confirmed they had made the donations and said they strongly believed in the governor’s mission.

Texas engineer Ronald Roche, who has donated $500 to the fund, said Abbott’s busing initiative has become necessary because the federal government has failed to address “this migrant problem.” He first learned about the efforts watching the news and said that while he was compelled to donate, he is also supportive of state taxpayer funds being used.

“States have a right to protect themselves,” he said. “If the federal government’s not doing it up to the level, I think any state… ought to use their own money. And that’s money well spent.”

While the bulk of the donations in which a state was listed came from those living in Texas, residents in other states – such as Mellon – also offered support.

“This isn’t just a Texas problem,” said Peter D’Amato, a property manager in South Carolina, who donated $100. “Texas drew the short straw being on the border, but it’s a national issue and they need some relief, and these folks need to find refuge in the sanctuary cities that invite them.”

Samay Rajan Verma, a 19-year-old college sophomore at Elmhurst University, a Christian college in Illinois, told CNN he supported the program because he wants people to “see the value of legal immigration,” saying his Punjabi parents entered the country legally and had to re-start their schooling. “They did a lot just to be here and to be successful in the United States. … I feel like the American people aren’t really realizing that this is really a slap on the face of all the legal immigrants that came here.” Verma donated $25 to Abbott’s efforts.

A $2,000 donation, meanwhile, was listed as coming from a progressive Washington, DC climate activist named Hendrik Voss.

When reached by CNN on the phone number provided to the state, Voss said he was shocked – then angry – to hear that he was listed in the donation data.

“I can say with 1,000% certainty that I’ve never given a cent to Gov. Abbott’s dehumanizing and racist publicity stunts,” he said in an interview. In reaction to the news, he said he had made an immediate donation to a local nonprofit to help support migrants who are being bused to DC.

(Copyright (c) 2024 CNN. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

Join our Newsletter for the latest news right to your inbox