With GOP House members saying their probe of the Biden family’s financial dealings has now spread to nine family members, it appears that troubled son Hunter’s entanglements may only be the beginning of the investigation.

The question now is whether the House Oversight Committee will expose anything that rises to a level that would interest Department of Justice criminal investigators, or if their probe will just shine light on a world of access, favors, and self-dealing that while unsavory is probably not illegal.

The committee’s chairman, Representative James Comer, disclosed that “six additional members” of the president’s family “may have benefited” from deals that could pose a “national security threat.” He added: “The Biden family enterprise is centered on Joe Biden’s political career and connections.” 

Mr. Comer attributed the burgeoning of his investigation to a research trip he took to the Department of the Treasury, where he and colleagues — including Representative Marjorie Taylor Greene — combed through what he called “thousands of pages of financial records related to the Biden family.” Those records, Mr. Comer asserts, confirm the investigation’s importance.

The treasury department last month gave Mr. Comer’s committee “in camera access” — the phrase comes from the Latin “in chambers,” and means “private” —  to Suspicious Activity Reports related to Hunter Biden and the Biden family’s foreign business deals. Mr. Comer is now vowing to “pursue additional bank records to follow the Bidens’ tangled web of financial transactions.”

Those reports, creatures of the Bank Secrecy Act of 1970, require financial institutions to file with the Financial Crimes Enforcement Network whenever there is a suspected case of money laundering or fraud. They are not a signal of guilt, but of suspicion. However, they are protected by walls of law-enforcement secrecy, so the Treasury has thus far been mum on their contents. 

The Oversight Committee last month reported that the Bidens in 2017 received $1 million in payments from accounts related to a business associate of Hunter’s, Robert Walker. Messrs. Biden and Walker were then doing business in China. Records subpoenaed from Bank of America indicate that “at least three family members” benefited from those dealings. 

A spokesman for Hunter Biden’s legal team insists that the relevant accounts “belonged to Hunter, his uncle” — that’s the president’s brother, James —  “and Hallie – nobody else.” Hallie Biden was married to Hunter’s brother Beau, who died in 2015 from brain cancer. She and Hunter subsequently had a love affair, which has since ended. 

The committee describes its probing as motivated by concern that “the Biden family has been targeted by foreign actors,” which could prompt a “national security threat.” Mr. Comer and his associates are not the only ones worried, as the Department of Justice has opened its own investigation into Hunter Biden’s taxes and possible misrepresentations relating to the purchase of a gun.

The mushrooming scope of these investigations — the Oversight Committee names an “unknown Biden” as a target of interest — could soon threaten not just the lesser Bidens, but the president himself, allegedly the “the Big Guy” referred to in correspondence recovered from the laptop reportedly owned by Hunter Biden and left at a Delaware repair shop.  

Reflecting on the broadening inquest, a law professor at George Washington University, Jonathan Turley, observes, “The investigation into the Bidens has made many in the Beltway uncomfortable. Influence peddling has long been the favored form of corruption in this city, but few families seem to have cashed into the extent of the Bidens.”