WASHINGTON — Congressional investigators this week grilled President Donald Trump’s personal attorney over a scuttled plan to open a new tower in Moscow, as lawmakers again expanded the scope of various inquiries into Russian meddling in the 2016 presidential election, sources familiar with the interviews told NBC News.

Long-time Trump ally Michael Cohen’s appearances before the House and Senate Intelligence Committees on consecutive days this week offered the panels greater insight into the inner workings of the president’s business empire and how it considered expansion into foreign markets like Moscow.

Sources familiar with Cohen’s interview Tuesday with the House panel said there was an extended focus on emails he received in 2015 from Felix Sater, a former Trump associate with a criminal past, about a potential deal to open a Trump Tower in the Russian capital. Cohen has downplayed those conversations, in which Sater bragged about his access to top Kremlin officials, saying it was about "a real estate deal and nothing more."

Participants also described often contentious exchanges between interviewers and Cohen’s attorney, who sought to cut off questions he saw as outside the committee’s purview. But Rep. Michael Conaway, R-Texas, who is leading the committee’s Russia probe, said Cohen answered his questions to his satisfaction and saw no need to invite him back.

Rep. Adam Schiff of California, the top Democrat on the Intelligence Committee, also described Cohen as “fully cooperative with the investigation.”

“Throughout the course of the investigation, from time to time we have attorneys that object to particular questions that are doing their job,” Schiff said.

During a marathon series of questioning in the House interview, there was at least one lighter moment. A Democratic congressman asked Cohen if he had ever used an alias in the past, raising one in particular: Michael Hacking. Cohen explained it was related to a taxi company he had owned — hack in this case being a reference to New York’s yellow cabs.

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“They really thought they had him, that this was an alias he used to hack into people’s phones. It was almost too good to be true,” said Republican Rep. Peter King, who as a New Yorker was one of the few present who immediately saw the humor in the exchange. “It was a moment of levity. I don’t know if the Democrats found it as funny as I did.”

Cohen had been scheduled to appear privately before the Senate Intelligence Committee last month, a meeting that was cut short after committee staff discovered that Cohen had released his prepared statement to reporters before his appearance. Though senators then called for a public hearing, Cohen ultimately was allowed to answer questions in private on Wednesday. That interview went even longer than what was a six-hour appearance before the House the day before.

Senate staffers also questioned Cohen extensively about the Trump Tower Moscow deal, according to a Congressional official familiar with the interview. The idea was to establish a record that will allow for better questions from senators when Cohen is summoned back for public testimony, the official said.

In his initial statement, Cohen, who served as executive vice president and special counsel at the Trump Organization, denied any personal role in Russia's involvement in the election, and said his reputation had been damaged by the "entirely and totally false" accusations in the "lie-filled dossier" about Trump that was prepared by former British spy Christopher Steele.

Related: Yes, The Russia-Trump Investigation is Real

After Cohen’s appearance this week The Washington Post reported that the dossier in question, which initially began as opposition research for an unnamed Republican campaign, was ultimately financed by an attorney with close ties to Hillary Clinton’s campaign and the Democratic National Committee.

Conaway, who took over the Intelligence Committee’s Russia investigation in April, said committee members were “actively pursuing as much information about the dossier that we can,” but did not offer a timeline for when the House would conclude its work.

“I have no interest in prolonging this beyond one second longer than it needs to,” he said. “We are going to keep pushing forward — but we are going to do a thorough investigation, and that takes some time.”

Also this week, the House committee interviewed former Obama deputy national security adviser Ben Rhodes and Brad Parscale, the former digital director for Trump’s presidential campaign. The House committee will interview former Trump adviser Carter Page next Thursday.

Both the House and Senate Intelligence Committees will hold public hearings next week to hear testimony from officials from Google, Facebook and Twitter about how foreign actors used their platforms to influence the political discourse and ultimately the election in the U.S.

Republican-led House committees announced separately this week, in tandem, that they would open additional probes into an Obama-era uranium sale to Russia as well as the Justice Department’s handling of the investigation into Clinton’s use of a private email server.

Democrats accused the GOP of seeking to distract from the underlying Russia probes.

“Tragically this looks like Benghazi redux,” said Schiff, referring to a special House committee formed to probe the 2011 attack on a U.S. diplomatic compound in Libya when Clinton served as secretary of state. “There just seems to be no end to the appetite to investigate Hillary Clinton. This is now I think also the second or third investigation prompted by presidential tweet.”

Democrats and Republicans on the Senate Judiciary Committee, meanwhile, seem to have agreed to press separate issues of interest related to the 2016 election. Chairman Chuck Grassley, R-Iowa, this week also pressed the Justice Department to allow testimony related to the uranium sale, while Democrats continue to focus on potential collusion between the Trump campaign and Russian officials.

"We have decided that each side is going to take a course and we'll share, and if the other side wants to participate, they can," said Sen. Dianne Feinstein, D-Calif., the ranking member of the committee.

"She wants to do what she wants to do, and we're doing a lot of things together," Grassley said. "Over 30 years I've been an equal opportunity investigator."