Federal investigators allegedly secretly wiretapped former Donald Trump campaign manager Paul Manafort before and after the 2016 election, according to a CNN report Monday.

Manafort first came under surveillance after a secret court order authorized it for investigators who were looking into work he did on behalf of a pro-Russia Ukrainian political party, CNN reported. He came under surveillance again as part of the FBI’s investigation into whether Trump’s campaign actively colluded with Russian officials to sway the outcome of the 2016 presidential election.

As CNN reported:

Some of the intelligence collected includes communications that sparked concerns among investigators that Manafort had encouraged the Russians to help with the campaign, according to three sources familiar with the investigation. Two of these sources, however, cautioned that the evidence is not conclusive.

Manafort, who served as Trump’s campaign manager for several months in the summer of 2016, is one of several allies of the president deemed a “person of interest” by Robert Mueller, the special counsel overseeing the Justice Department’s probe of Russian interference in the presidential campaign. Manafort is also under scrutiny by congressional committees investigating the Trump campaign’s Russia ties.

In July, FBI agents raided Manafort’s home as part of their investigation. A New York Times story also published Monday detailed that raid, as well as other aspects of Mueller’s probe. Among the revelation by the Times is that Mueller’s prosecutors reportedly told Manafort after the raid that they would indict him.

Manafort has faced intense scrutiny for his business dealings with Russia and Ukraine. In June, he retroactively registered as a foreign agent roughly 10 months after his undisclosed lobbying work in Ukraine was first revealed.

In addition to the lobbying work, federal investigators are reportedly interested in Manafort’s real estate deals as well as his ties to Russian oligarchs.

Earlier this month, Manafort’s spokesman, Jason Maloni, testified before the federal grand jury that Mueller has impaneled as part of his investigation. Maloni met with the grand jury for more than two hours.

And in July, the Senate Intelligence Committee subpoenaed Manafort after he declined to testify about a meeting he and other Trump officials had with a Russian lawyer who claimed to have damaging information about presidential rival Hillary Clinton to offer the Trump campaign. The committee withdrew its subpoena after Manafort agreed to continue talking to investigators and turn over documents.

Sen. Dianne Feinstein (D-Calif.) said Sunday that the committee would again invite Manafort to testify and is “likely” to subpoena him if he refuses to comply.

Maloni responded to the CNN report later Tuesday and called on the Justice Department to “release any intercepts” that may have been recorded.

NEW - Manafort spokesperson releases statement about wire tap reports - says "if true" calls on DOJ to release "any intercepts" pic.twitter.com/QtbzbvT7YD — John Santucci (@JTSantucci) September 19, 2017

This article has been updated with further comment from Maloni and with details on investigations involving Manafort.