The revelations to Sen. Chuck Grassley's office came Tuesday as the Treasury Department's inspector general for tax administration, the government's chief watchdog for the Internal Revenue Service, formally reopened its investigation into the matter by re-interviewing Ms. O'Donnell.
"It is an active investigation now," Ms. O'Donnell told The Washington Times after meeting with the same Treasury agent who first informed her in January that her tax records were improperly accessed.
She declined to be more specific about what the agent questioned her about in Tuesday's session.
But Mr. Grassley, an Iowa Republican who serves on the Judiciary and Finance committees, said he was concerned by the information Delaware state officials shared with his investigators.
Specifically, Mr. Grassley's staff was told that a Delaware state investigator asked for and received permission from his boss on a Saturday to access Ms. O'Donnell's tax records based on a local newspaper article about a civil lien. The lien, it turned, out was issued erroneously.
Mr. Grassley said he was concerned that a simple newspaper article that alleged no criminal wrongdoing could be used to pierce one of America's most protected privacies, tax information.
He is pressing for more information on what safeguards the IRS is using to stop such snooping and whether the system used by Delaware state officials may amount to an unmonitored back door into confidential IRS tax records.
"The state says it looked at Ms. O'Donnell's federal records because of a newspaper article describing a federal tax lien against her," Mr. Grassley said. "Does the state look at every taxpayer who faces a federal lien or only those who happen to appear in a newspaper article? Is it routine for a state employee to email his boss about looking at a taxpayer's records on a Saturday, when the article appeared? It's hard to evaluate what happened in the O'Donnell case without answering these questions, and I'll continue to work to get more information."
Mr. Grassley's staff also was told that Delaware officials do not think they kept any of the computerized records showing when their investigators accessed Ms. O'Donnell's tax records because such searches are stored for only three months before they are deleted or destroyed.
The access was believed to have occurred in March 2010, the same month Ms. O'Donnell formally launched her Senate campaign that shocked the Delaware establishment by defeating Republican favorite Michael Castle in the primary election.
"So far, it appears the department destroys the access records after a short amount of time," Mr. Grassley said. "That's puzzling. Unless the IRS has a back-up, and I hope the IRS does, there's no way to know how and when Delaware state employees accessed Christine O'Donnell's federal tax records."
Mr. Grassley also noted that if records are routinely destroyed, this also would cast doubt on the state explanations.
"If the records were destroyed, it's also hard for the state to support its statement that its record access occurred only in response to a public report, and not before," he said.
The timing of when Ms. O'Donnell's records were accessed remains in dispute. Even though they claim to have no records, Delaware state officials have said they believed the access occurred on March 20, 2010, only after a public story about the IRS lien against Ms. O'Donnell was published.
But Ms. O'Donnell told The Times last week that when investigators alerted her in January that her confidential tax records were breached three years ago, they told her the date was March 9, 2010.
That date was the same day Ms. O'Donnell scheduled a news conference to announce her Senate run. It's also the same date the IRS admitted the lien against her was mistakenly generated by a computer and sent to Delaware.
The Times reported last week that the Treasury inspector general for tax administration had discovered at least four cases in which a candidate's or donor's tax information was inappropriately searched.
In one case, the investigator said the violation was willful and referred it to the Justice Department, which declined to pursue the case.
Rep. Darrell E. Issa, California Republican and chairman of the House Committee on Oversight and Government Reform, said last week he was baffled that the Justice Department declined to prosecute a government employee who apparently knowingly pried into tax records of a political candidate or donor, and that there should be a way for victims to know their rights have been violated.
Delaware state officials could not be reached for comment Tuesday, but Patrick Carter, director of the state's division of revenue, said last week that they believe employee "properly conducted a review of federal tax records." Mr. Carter identified the employee as David Smith, an auditor.
"A state Division of Revenue investigator accessed records on or after March 20, 2010, following information that came to the attention of the division," Mr. Carter said in a statement. "The record access led the state revenue investigator to conclude there was no basis for further state investigation of a taxpayer and no action was taken by the state Division of Revenue against the taxpayer."
He said that his division reviewed the accessing in December and "again found state access of the records of the taxpayer was part of a typical review and was not improper."