Secretary of Commerce Wilbur Ross has always been the Trump administration’s scandal waiting to happen. Not the only scandal, mind you, but the scandal with the greatest potential to expose just how sordid and conflicted this president’s inner circle really is.

A longtime associate of Trump who was once described as “The Bottom-Feeder King,” Ross slid through the confirmation process by skirting questions from key Democrats about banking arrangements that intersected with those of Russian oligarchs. He was able to do that because Senate Commerce Committee chair John Thune (R-SD) and Senate majority leader Mitch McConnell (R-KY)were determined to grease the wheels for a Wall Street insider with a history of keeping Trump afloat financially.

Despite the fact that Senator Elizabeth Warren (D-MA) warned that Ross “has shady ties to Vladimir Putin’s Russia,” the full Senate confirmed Trump’s nominee on a 72-27 vote. (A number of Democrats joined Republicans in giving Ross a pass—in part because the nominee sent moderate signals on issues like climate change.)

But it was only a matter of time until the 79-year-old billionaire—whose ownership role with the Bank of Cyprus, which “caters to wealthy Russians,” was never adequately examined during the confirmation process—would end up on the receiving end of the scrutiny that should have denied him a place in the cabinet. Now the time has come for the checking and balancing that Ross avoided when the Senate failed to perform due diligence regarding his nomination.

Ross’s controversial financial arrangements are making headlines following the release of millions of documents from the Bermuda-based law firm Appleby, which were leaked to the German newspaper Süddeutsche Zeitung. According to NBC,

The documents consist of emails, presentations and other electronic data. These were then shared with the International Consortium of Investigative Journalists—a global network that won the Pulitzer Prize this year for its work on the Panama Papers—and its international media partners.

Some of the so-called “Paradise Papers” were shared with NBC, which reported that

Wilbur Ross, the commerce secretary in the Trump administration, shares business interests with Vladimir Putin’s immediate family, and he failed to clearly disclose those interests when he was being confirmed for his cabinet position. Ross—a billionaire industrialist—retains an interest in a shipping company, Navigator Holdings, that was partially owned by his former investment company. One of Navigator’s most important business relationships is with a Russian energy firm controlled, in turn, by Putin’s son-in-law and other members of the Russian president’s inner circle.

Ross knows he’s in trouble. He’s doing interviews in which he claims that there was “nothing improper” about his investments—and his secrecy with regard to them. But it’s unlikely he’ll get off the hook as easily as he did last February, when Thune and the Commerce Committee failed to provide proper oversight.

Common Cause has now called on the inspector general of the Commerce Department to investigate Ross’s

[s]ignificant investments in a shipping company closely linked to Russian President Vladimir Putin’s inner circle that came to light through the “Paradise Papers.” Financial filings reveal that Ross’s investments include between $2 and $10 million dollars in Navigator Holdings, which takes in millions of dollars annually for transporting natural gas for Sibur, a Russian energy giant partially owned by Putin’s son-in-law and also a Russian oligarch with close ties to the Russian President. At a time when the U.S. has imposed sanctions against the Russian Energy sector over Russia’s annexation of parts of Ukraine, Navigator has actually expanded its business with Sibur.

Karen Hobert Flynn, the president of Common Cause, points out that

Secretary Ross was not forthcoming in his confirmation hearings and we are urging the Inspector General to fully investigate the business holdings of the Commerce Secretary—particularly those with ties to the Kremlin. These latest revelations are part of a disturbing pattern of Trump Administration officials seeking to hide their links to Russian business interests and members of Vladimir Putin’s inner circle.

At its Blueprint for a Great Democracy Conference this week, the watchdog group is expected to ramp up pressure on the inspector general to conduct a prompt inquiry and to make findings publicly available “to shed light on the deliberately hidden offshore investments of the Commerce Secretary.”

As more details come out, Thune and Republican members of the Commerce Committee are facing new questions about their failure to provide adequate oversight—and new demands for the thorough examination of Ross that should have been conducted before his nomination was confirmed.

Connecticut Senator Richard Blumenthal, a Democrat who grilled Ross during Commerce Committee deliberations last winter and who ultimately opposed confirmation of the commerce secretary, is already making those demands—pushing for that inquiry by the Commerce Department’s inspector general and raising the prospect that Ross will need to explain himself in new testimony before the committee.

“In concealing his interest in these shipping companies—and his ongoing financial relationship with Russian oligarchs—Secretary Ross misled me, the Senate Commerce Committee, and the American people,” said Blumenthal. “Secretary Ross’ financial disclosures are like a Russian nesting doll, with blatant conflicts of interest carefully hidden within seemingly innocuous holding companies.”

Blumenthal is right when he argues that

Only after a thorough investigation can the American people be sure that Secretary Ross really has their best interests at heart—and that he hasn’t prioritized his own personal profits or those of Vladimir Putin or his Russian business partners.