Christine O'Donnell, the Tea Party star with a chequered past and uncertain future, is said to be under federal investigation for misusing donations made by supporters during her failed election campaigns.

The Associated Press reported that a criminal probe has been opened to examine whether O'Donnell broke the law by using campaign funds to pay for personal expenses during the Delaware Republican's attempts to win a seat in the US Senate.

But O'Donnell responded by saying the news was evidence of "thug tactics", lashing out in a statement that claimed a sinister plot against her by both the Republican and Democratic parties and suggested that Vice President Joe Biden, a former Delaware senator, was involved in manipulating the FBI.

O'Donnell's case has been assigned to two federal prosecutors and two FBI agents in Delaware but has not been brought before a grand jury, according to AP reporters Ben Nuckols and Mattew Barakat, quoting a "person with knowledge of a federal campaign-finance investigation," who they said could not be named in order to protect the identity of a client.

Delaware's News Journal also reported that O'Donnell was "the subject of a federal criminal probe to determine if she illegally used campaign money to pay personal expenses," quoting "a federal source in a position to know".



In her statement on Wednesday evening, O'Donnell said: "We've been warned by multiple high-ranking Democrat insiders that the Delaware Democrat and Republican political establishment is jointly planning to pull out all the stops to ensure I would never again upset the apple cart.

"Specifically they told me the plan was to crush me with investigations, lawsuits and false accusations so that my political reputation would become so toxic no one would ever get behind me. I was warned by numerous sources that the political establishment is going to use every resource available to them.

"So given that the king of the Delaware political establishment just so happens to be the Vice President of the most liberal presidential administration in US history, it is no surprise that misuse and abuse of the FBI would not be off the table."

Accusations of financial irregularities have dogged O'Donnell for months, even before O'Donnell shot to fame in September after her surprise victory in the Delaware Republican primary – thanks to a surge of support from the Tea Party movement and backing from the likes of Sarah Palin and Rush Limbaugh.

On the eve of the Republican primary, O'Donnell's former campaign manager accused her of being a "complete fraud," who lived on campaign donations "while leaving her workers unpaid and piling up thousands in debt."

Shortly afterwards, the watchdog group Citizens for Responsibility and Ethics in Washington (Crew) filed a complaint with the Federal Election Commission, claiming that O'Donnell had used more than $20,000 in campaign funds for personal use. O'Donnell denied the charges, saying: "I personally have not misused campaign funds."

After the news broke, Crew's executive director Melanie Sloan told the Washington Post that she welcomed the inquiry.

"It's quite clear that O'Donnell was misappropriating money for personal expenses," Sloan said. "My understanding is that she treated the whole thing like her piggy bank."

After winning the nomination O'Donnell received $7.3m in donations for her election campaign, which ended in heavy defeat despite her lavish spending. O'Donnell's controversial past, limited CV and erratic campaigning style saw her crushed at the polls by the unfancied Democrat Chris Coons.

In a lengthy post-election investigation into the O'Donnell campaign's spending, the News Journal reported earlier this month that her campaign had retained more than $900,000 of the $7.3m total. It also highlighted statements to the Federal Election Commission that O'Donnell's operation paid her sister $26,000 and her mother $3,500 for work during the campaign.