The report recommends the special counsel take civil action, including possibly asking a judge to invalidate the election of the first-year Republican attorney general and to declare the office vacant.
The left-leaning Alliance for a Better Utah filed the complaint with the lieutenant governor's office in March, alleging a dozen violations on Swallow's disclosure forms.
"We've always hoped and felt confident that the case was strong," said alliance executive director Maryann Martindale, who had not seen the report.
"We feel really strongly that [the matters in the complaint] are against the code, that he's broken the law if he's found to have violated those. So that's what we expect to see," she said. "We'll be really disappointed if that's not the response."
After researching the alliance's complaint, the lieutenant governor's office dismissed nine allegations, but deemed three others worthy of further investigation.
Allegations from the alliance included a claim that Swallow tried to conceal his interest in a company, P-Solutions, and $23,500 in payments he received from Richard Rawle, the late founder of the Provo-based Check City payday-loan chain.
The money for those payments came directly from funds Rawle received from indicted St. George businessman Jeremy Johnson, who had hired Rawle to help him avoid a Federal Trade Commission lawsuit.
When Swallow learned he had received Johnson's money about 14 months later he returned it and asked for payment from a different account.
Swallow has said the money was paid for consulting work he did on a cement project in Nevada, an assertion Rawle backed in a declaration days before his death last December.
The Salt Lake Tribune reported in January that Swallow removed himself as a manager of P-Solutions on March 15, 2012, the same day he filed his candidate financial-disclosure form, and transferred his interest to his wife.
Swallow's attorneys argued that the complaint against their client was frivolous.
They said Swallow was advised by an expert in trust law that he was not required to disclose the company's income because it went into a trust to benefit his children although his children's trust is not listed on corporate records filed with the state.
They also maintain that, if Swallow should have disclosed the payments and business interests, he should be allowed to file an amended report, rather than face more severe consequences.
A message left Wednesday for Swallow's attorney Rod Snow was not returned. The governor's office declined to comment Wednesday on the investigation.
Under state law, the lieutenant governor normally would have forwarded the alliance's complaint to the attorney general's office for action.
But because of the obvious conflict of interest, the Legislature rushed through a bill at the end of the 2013 session allowing the lieutenant governor to appoint a special counsel in complaints against the attorney general.
The lieutenant governor's office then under Lt. Gov Greg Bell hired the firm of Snell & Wilmer in July to investigate. Since then, Bell has stepped down and former Rep. Spencer Cox, who was the first legislator to call for impeachment proceedings against Swallow, has taken over as Gov. Gary Herbert's lieutenant governor.
The report from the lieutenant governor's office will also go to a House committee investigating Swallow, who has denied any wrongdoing. Swallow gave sworn testimony to the lieutenant governor's special counsel for two days. House investigators have requested a transcript, but Swallow and his former employer, Softwise Inc., have yet to give permission to release the interview.
Other Swallow news
• The Utah House investigation of Attorney General John Swallow is expected to enter a new phase next month when a special committee begins interviewing witnesses and presenting evidence in public hearings.
• The probe's price tag is approaching $1.5 million, including $300,000 spent on court proceedings trying to gain access to information.
• Third District Judge Su Chon has signed an order granting the committee access to copies of hard drives and servers in the attorney general's office in an attempt to recover lost emails, calendar entries and other electronic data.