President Donald Trump. REUTERS/Jonathan Ernst/Aly Song/File Photos

The Trump administration may be entangling itself in another ethical landmine.

In this case, the White House could have violated its own ethics rules with at least two hires, a New York Times and ProPublica investigation found.

One potential conflict involves Michael Catanzaro, who is the White House's top energy adviser. Until last year, The Times and ProPublica found, Catanzaro was working as a lobbyist for the fossil-fuel industry and had clients like Devon Energy of Oklahoma and Talen Energy of Pennsylvania.

Those two companies were stalwart opponents of President Barack Obama's environmental regulations, like the Clean Power Plan, which sought to promote the use of alternative energy sources. Trump signed an executive order undoing the plan in March. As the White House's top energy adviser, Catanzaro will handle many of those same issues.

Another possible ethical dilemma involves Chad Wolf. The Times and ProPublica investigation found that Wolf, the chief of staff at the Transportation Security Administration, spent the past several years lobbying the TSA to secure funding for a new screening device for carry-on luggage that could cost hundreds of millions of dollars. Wolf's new role as the TSA's chief of staff puts him in a prime position to make the decision he had previously spent years lobbying for.

In another instance, two officials who joined the Department of Labor were direct recruits from Washington's lobbyist circle. According to the investigation, before joining the White House, the two officials were opponents of Obama's labor policies, including the fiduciary rule, which stipulated that financial advisers had to act in the best interest of their clients when providing retirement advice.

Determining whether the White House violated its own ethics rules by hiring lobbyists is a murky area, however, because the investigation also found the Trump administration had secretly been issuing waivers to the rules it first introduced in a stated effort to increase transparency.

Barack Obama onstage at his farewell address in Chicago. AP Photo/Pablo Martinez Monsivais Trump signed an executive order in January eliminating an Obama rule mandating that lobbyists could not accept jobs in federal agencies they had lobbied. Trump's elimination of that rule blurred ethical standards for at least 4,000 executive hires, the investigation by The Times and ProPublica found.

Examining the degree to which ethical misconduct may have occurred is next to impossible now, according to Walter M. Shaub Jr., the director of the Office of Government Ethics.

Though the Obama administration also issued ethical waivers, it did so under a narrow set of circumstances. Those waivers also had to be disclosed for public inspection. Now that it is no longer required to disclose waivers, Shaub told The Times that "there's no transparency, and I have no idea how many waivers have been issued."

Other ethical landmines

While it is not uncommon for lobbyists to become government officials — the Obama administration had 65 former lobbyists on its payroll at one point — Trump's critics have repeatedly scrutinized the current administration's overall lack of transparency and its ethical conduct.

On Friday, for example, the White House announced that it would not release its visitor logs and that they would be kept secret for five years after Trump leaves the White House. The move, which drew instant backlash from government-accountability advocates across the country, means the White House will not be releasing information about bankers, lobbyists, or other officials who may visit the grounds in an effort to influence government policy.

Trump has also refused to release his tax returns since he launched his presidential campaign, saying he cannot disclose them because they are under audit. The IRS said during the campaign that Trump had the freedom to release his tax returns, regardless of whether he was under audit.

After thousands protested in cities across the US on Saturday calling for the president to release his tax returns, Trump tweeted his response on Sunday that "the election is over!"

Ivanka Trump and her husband, Jared Kushner. REUTERS/Jim Bourg

The president ignited numerous ethical controversies with his initial staff appointments, including his decision to make his son-in-law, Jared Kushner, a senior adviser. Since assuming his role, Kushner has steadily gained influence in his father-in-law's inner circle and taken on more responsibility, including visiting Iraq and meeting with the Iraqi prime minister before Secretary of State Rex Tillerson did.

The White House also recently announced that Kushner would be head of the new White House Office of American Innovation, which will aim to use business tactics to overhaul the federal government.

In late March, it was announced that Trump's daughter Ivanka, who is Kushner's wife, would be assuming a "voluntary" role in her father's administration and would function as Trump's "eyes and ears" in the White House. She also received security clearance and an office in the West Wing.

After swift backlash against the opacity of Ivanka's new role and the conflicts of interest raised by her assuming a White House position while maintaining ownership of her namesake fashion brand, it was announced that her employment would no longer be voluntary and that she would be subject to the same ethics rules imposed on other federal employees. Her new position is that of an unpaid adviser.