(CNN) The House intelligence committee and Fusion GPS struck a deal to have the intelligence firm's co-founder voluntarily testify before the committee next week.

The agreement for Glenn Simpson to testify behind closed doors Tuesday appears to be a thaw in a fight between the committee and the firm that spilled over into the courts.

The committee had issued a subpoena for Simpson's testimony and is also seeking bank records from Fusion GPS, which has filed an injunction in court to try to stop the release of the records.

Reps. Mike Conaway of Texas and Adam Schiff of California, the Republican and Democrat leading the panel's Russia investigation, said in a joint media appearance they had reached the agreement for Simpson to voluntarily appear and they would withdraw the subpoena for his testimony at that time.

"We wanted to secure his testimony and we were able to work out an agreement today," Schiff told reporters.

Joshua Levy, an attorney for Fusion GPS, said Simpson had agreed to testify after the committee agreed to the same conditions as both the Senate intelligence and judiciary committees. Simpson testified before the Senate judiciary committee for 10 hours earlier this year in closed session. Levy said Simpson is also cooperating with the Senate intelligence panel.

"Mr. Simpson will be appearing voluntarily, he will tell the truth, the subpoena will be withdrawn, and he will be able to maintain Fusion GPS' privileges and honor its legal obligations," Levy said. "Through a voluntary interview, he has the ability to appear with counsel, to assert privileges and to answer questions that he chooses to answer."

Simpson and Levy were behind closed doors with the committee for roughly three hours. The lawmakers and Levy all said that the agreement for Simpson to testify was separate from the court battle over Fusion GPS' bank records.

"It has nothing to do with the courts at this stage," Conaway said.

Last month, Fusion GPS partners Peter Fritsch and Thomas Catán also appeared before the House panel, where they invoked their constitutional right not to answer questions after they were subpoenaed.

Fusion GPS has been at the center of the controversy over the Russian dossier that was compiled by former British intelligence officer Christopher Steele and included salacious allegations against Trump.

The dossier has helped fuel the ongoing investigations into Trump and Russia, including the special counsel probe led by former FBI Director Robert Mueller. CNN reported in February that investigators had been able to corroborate some information in the dossier, although not the most salacious allegations about Trump and his Russia ties.

Last month, Perkins Coie, the law firm for Hillary Clinton's 2016 presidential campaign and the Democratic National Committee, has acknowledged its clients' role in paying for the dossier, which sparked a new wave of accusations from Trump and some Republicans that it was in fact the Democrats who were colluding with Russia. Trump told reporters late last month that the Clinton campaign and DNC's involvement with the dossier was a "very sad commentary on politics in this country."

"Hillary Clinton always denied it. The Democrats always denied it, and now, only because it is going to come out in a court case, they said yes they did it. They admitted it and they are embarrassed by it. I think it is a disgrace," he said.

The court battle over Fusion GPS' bank records appeared to have been settled in late October to provide some financial records to the House committee through its bank. But the agreement evaporated after Fusion GPS said the committee sought records about any of the firm's transactions with 10 law firms, a media organization, journalists and two other businesses, plus records about people who worked for Fusion GPS.

The House committee asked for 112 of almost 400 records about Fusion GPS from TD Bank. "None of the those demands are pertinent to the committee's 'Russia investigation,'" Fusion GPS' injunction request said.

The House panel "has not requested these records in furtherance of any legitimate legislative purpose, but instead to annoy, harass and punish Fusion GPS," the intelligence firm said in court.

Jack Langer, a spokesman for House intelligence committee chairman Devin Nunes, R-Califonria said the committee responded in court on Tuesday. The filing was sealed, but a redacted version is expected to be made public later Wednesday, he said.

In addition to Perkins Coie, the Washington Free Beacon, a conservative news website, said it hired Fusion GPS for research on Trump during the Republican primary election last year. Their engagement ended before Steele took part in the effort.

Fusion GPS said Perkins Coie paid it $1.02 million for fees and expenses in the 2016 presidential campaign and that Orbis Business Intelligence, the company that created the dossier by former British intelligence officer Christopher Steele, earned $168,000 from Fusion GPS.