The contribution surprised Reyes, who said Hatch has repeatedly promised to remain neutral in the June 26 GOP primary showdown.
"My understanding from my conversation with the senator was that he wasn't going to take a position," he said. "I believed him."
Reyes has not asked Hatch for a donation but is considering doing so.
Hansen said Hatch has no intention of giving Reyes a contribution at this time but added that the senator will stick to his word and give no endorsement.
Hatch, who faces his own GOP primary against former state Sen. Dan Liljenquist, has other ties to the Swallow camp. One of Hatch's chief campaign strategists, Jason Powers, is also advising Swallow. And Jessica Fawson, who works for Hatch's Senate office, is acting as Swallow's campaign manager.
Powers and Fawson have worked on the same campaigns since 2006, including Attorney General Mark Shurtleff's 2008 re-election effort and his short-lived 2010 run for Senate. They also teamed up to help the conservative group Club for Growth in the 2010 convention fight that unseated Sen. Bob Bennett and advised Mike Lee's successful Senate campaign later that year.
"We both respect each other's work," Fawson said.
Hatch hired Fawson in 2010. She moved to his D.C. office and worked as part of his press team. She asked for and received a transfer to the Salt Lake City office in January so she could work on Swallow's race. Swallow is Shurtleff's deputy in the attorney general's office and is officially endorsed by Lee.
Fawson made $53,000 in fiscal 2011, but Hatch spokesman Matt Harakal said she has taken a pay cut and is working part time. Fawson works for Hatch in the mornings and Swallow in the afternoon.
She has received $30,000 in salary and reimbursements from the Swallow campaign, according to the latest state disclosure.
The only other Hatch staffer splitting time between a campaign and official Senate duties is Heather Barney, a Utah-based spokeswoman who also is working for Hatch's campaign.
Powers and Fawson said they were unaware of Hatch's contribution until the Swallow campaign received the check.
Hatch made other contributions through his OrrinPAC, including $10,000 each to the campaigns of Mia Love and Chris Stewart. Love is the Republican candidate in Utah's 4th Congressional District and Stewart is the GOP candidate in the 2nd District.
Sen. Orrin Hatch used his political action committee to give contributions to a few candidates and outside organizations in April.
$10,000 • Mia Love, Republican candidate, 4th Congressional District
$10,000 • Chris Stewart, Republican candidate, 2nd District
$1,000 • John Swallow, Republican candidate, attorney general
$200 • Dixie Junior Livestock Auction
$5,000 • ConSource, online library on constitutional history
Source: Federal filings