The FBI handed over documents to House investigators this week detailing how senior law enforcement officials handled “surveillance records,” involving Trump associates, along with documents on the agency’s informant program.

House Intelligence Committee Chairman Devin Nunes (R-CA) warned on Sunday that he would take additional measures against Justice Department officials unless they complied with an April subpoena requesting documents regarding the agency’s surveillance of the Trump campaign.

“The deadline is this week,” the California Republican told Fox News host Maria Bartiromo. “So if documents begin to be turned over tomorrow and a clear way and path forward for everything else is not clear here in the next couple of days, there’s going to be hell to pay by Wednesday morning.”

Investigators on the Hill will have an opportunity to learn more about the extent to which senior FBI and Justice Department officials knew about surveillance of the Trump campaign. On Friday, House Oversight and Judiciary Committees received over than 1400 pages of documents “relating to senior FBI or Justice Department officials’ requests to review or manage surveillance records that either involve or mention the Trump campaign or Trump administration,” according to Politico.

Freedom Caucus leader Rep. Mark Meadows (R-NC) downplayed the transfer, branding reports that bureau and Justice Department officials have increased cooperation with lawmakers as “false.”

“New reports of DOJ/FBI compliance with document requests are NOT accurate,” Meadows tweeted. “While they have turned over additional documents, the new documents represent a small percentage of what they owe.”

“The notion that DOJ/FBI have been forthcoming with Congress is false,” he added.

New reports of DOJ/FBI compliance with document requests are NOT accurate. While they have turned over additional documents, the new documents represent a small percentage of what they owe. The notion that DOJ/FBI have been forthcoming with Congress is false. — Mark Meadows (@RepMarkMeadows) June 23, 2018

Last month, Cambridge professor Stefan Halper was outed as an FBI informant who had interactions with three Trump campaign officials— Carter Page, George Papadopoulos and Sam Clovis.

The New York Post writes:

Halper made his first overture when he met with Page at a British symposium. The two remained in regular contact for more than a year, meeting at Halper’s Virginia farm and in Washington, DC, as well as exchanging emails. The professor met with Trump campaign co-chair Sam Clovis in late August, offering his services as a foreign-policy adviser, The Washington Post reported Friday, without naming the academic. … Days later, Halper contacted Papadopoulos by e-mail. The professor offered the young and inexperienced campaign aide $3,000 and an all-expenses-paid trip to London, ostensibly to write a paper about energy in the eastern Mediterranean region.

Public records show the Pentagon paid the foreign policy expert $282,295 on September 27, 2016.

The nature of the work is still unknown.

Reports of the documents making their way into the hands of lawmakers come after House Judiciary Committee Bob Goodlatte issued a subpoena for FBI agent Peter Strzok on Friday afternoon.

STRZOK: The House Judiciary Committee has subpoenaed FBI agent Peter Strzok to appear next week even though his lawyer signaled last week that he planned to testify voluntarily. pic.twitter.com/PRJG3OByvt — Kyle Cheney (@kyledcheney) June 22, 2018

Aitan Goelman, the embattled FBI agent’s lawyer, said his client is willing to testify voluntarily before Congress and will not seek immunity or invoke his Fifth Amendment rights.

Strzok is scheduled to appear before the Committee on June 27 at 10:00 a.m.