An ethics group late Friday published nearly 100 pages of previously unreleased State Department documents that the group says shows “a clear paper trail” between President Donald Trump’s lawyer Rudy Giuliani and Secretary of State Mike Pompeo before a Ukraine ambassador was abruptly recalled.

The documents were published by American Oversight, which calls itself a non-partisan and nonprofit ethics watchdog and Freedom of Information Act litigator investigating the Trump administration.

They appear to show two calls between Giuliani and Pompeo in March, around a month before former Ukraine ambassador Marie Yovanovitch, an anti-corruption expert, was abruptly called back to the U.S. in April and then removed from the post.

David Hale, undersecretary of state for political affairs, testified on Wednesday that Pompeo and Giuliani spoke on the phone twice in late March.

The information released Friday "reveals a clear paper trail from Rudy Giuliani to the Oval Office to Secretary Pompeo to facilitate Giuliani's smear campaign against a U.S. ambassador," Austin Evers, executive director of American Oversight, said in a statement.

Yovanovitch has told members of Congress in an impeachment inquiry that her reputation was smeared by Giuliani, including false allegationsthat she badmouthed Trump and was blocking corruption investigations by circulating a "do not prosecute" list and stymieing investigation into the Vice President Joe Biden and his son.

The allegations of a pressure campaign by Trump to get the Ukrainians to announce investigations into a conspiracy theory about the 2016 presidential election and the Bidens are central to the impeachment inquiry into whether Trump abused the power of his office for personal political gain.

The documents released Friday appear to confirm that Pompeo and Giuliani spoke on the phone on March 26, and that another call was scheduled between the two men for March 29 and that it took place.

One email appears to show Trump’s former personal assistant, Madeleine Westerhout, helping to connect Giuliani to Pompeo after there was trouble establishing a connection.

The documents do not say what Giuliani and Pompeo discussed. The March 29 call was scheduled for 20 minutes but lasted just four minutes, according to the documents, and the March 26 call was also just minutes long, the emails show.

A request for comment from the State Department was not immediately returned after the documents were released late Friday.

The emails also show that before the acting U.S. ambassador to Ukraine, Bill Taylor, took the job he was among six former Ukraine ambassadors who objected to "recent uncorroborated allegations" about Yovanovitch.

The April letter from Taylor and the five others says, "these charges are simply wrong."

Taylor told Congress he was asked to return to lead the embassy in Kyiv in May by Secretary of State Mike Pompeo. In his testimony, Taylor said his initial reservation about taking the job was because of the poor treatment of Yovanovitch.

The April 5 letter from Taylor and the former ambassadors cited recent articles by John Solomon, who at the time was an opinion contributor for The Hill, that claimed the embassy under Yovanovitch interfered with the ability of the Ukrainian prosecutor to investigate anti-corruption cases, and that she criticized Trump.

"If the attack on Ambassador Yovanovitch were to gain traction, it would be an injustice against her and against reformers in Ukraine," the letter to the State Department reads. "Allowing these attacks on a US Ambassador in the field to stand without rebuttal from senior leadership in the US government weakens the structure of our diplomatic engagement," it adds.

House Democrats are still waiting for documents from the State Department that they subpoenaed in connection with the impeachment inquiry.

American Oversight says this is just the first round of disclosures.

"The evidence is only going to get worse for the administration as its stonewall strategy collapses in the face of court orders," Evers said in the statement.