Update: Dr. Oz officially joins the Senate race in Pennsylvania

WASHINGTON — Pennsylvania Republican insiders say celebrity doctor Mehmet Oz is likely to join Pennsylvania’s U.S. Senate race, perhaps as soon as this week.

Fox News host Sean Hannity all but said the formal announcement will come Tuesday. At the end of his show Monday, hours after this report initially published, Hannity teased Oz’s appearance on his show Tuesday night saying he had a “huge announcement.”

“Hint: think midterm election,” Hannity added.

Widely known as Dr. Oz, he has already hired top campaign aides and has reached out to some Republican political leaders in the state, according to multiple Pennsylvania Republicans familiar with the matter.

He would be seeking the Republican nomination in one of the country’s most critical races, adding another jolt to a contest that already this month saw the early GOP front-runner, Sean Parnell, politically collapse amid abuse accusations from his estranged wife. Parnell had won former President Donald Trump’s endorsement in late August, but his abrupt downfall once again left a wide-open Republican field.

Political aides working with Oz did not immediately respond Monday to questions about his plans.

Oz, 61, whose climb to fame began when Oprah Winfrey introduced him to her massive audience more than a decade ago, would enter the contest with heavy name recognition — and enormous wealth that he is said to be willing to pour into the contest, but with little known about his political beliefs. The TV star appears to have been planning, or at least considering, a run for some time, though: He lived in New Jersey for years but switched to vote in Montgomery County last December, at his in-laws’ home in Bryn Athyn.

The race to replace Sen. Pat Toomey, a Republican who isn’t seeking reelection, could have far-reaching consequences. It’s one of a handful of contests likely to decide control of the Senate.

» READ MORE: Sean Parnell is out. What’s next for Republicans in Pa.’s 2022 Senate race?

Oz, who graduated from the University of Pennsylvania’s medical school and from its Wharton business school in 1986, would seemingly bring fame and status as a political outsider to the Republican primary but would also likely face questions about living outside the state and his sometimes controversial medical advice. He has promoted diet pills that other doctors have blasted as a sham.

Oz would enter a GOP field that includes Montgomery County developer Jeff Bartos, former Ambassador to Denmark Carla Sands, and conservative commentator Kathy Barnette. David McCormick, a hedge-fund manager who now lives in Connecticut, began meeting with top GOP officials and donors this week as he considers his own bid, though it’s unclear if he will join the contest.

This story has been updated.