The top Democrat on the House Intelligence Committee wants testimony from the former British spy who compiled an explosive dossier on President Donald Trump's alleged activities in Russia as part of the committee's investigation into the Kremlin's efforts to sway the U.S. election last year.

Rep. Adam Schiff of California, the ranking member, said Tuesday that he hoped to interview Christopher Steele, a former MI6 agent who put together the document that included salacious but unproven details of Trump's financial and sexual activities.

Schiff told MSNBC's Rachel Maddow he will "certainly be requesting [Steele's] testimony."

"If there's an issue about whether he is willing to come before the committee, I can say I am more than willing to go to him, and I know there are other members of the committee would join me in that," Schiff said.

Steele compiled the 35-page dossier as part of opposition research during the 2016 presidential campaign. While it made the rounds among media and lawmakers before the election, it was only made known to the broader public after CNN reported that the dossier's contents had been presented in January to then-President Barack Obama and Trump, the president-elect at the time, by top intelligence officials as part of an appendix to a report on Russia's election meddling. Buzzfeed later published the document in full.

Steele, who went into hiding after his connection to the dossier was made public, re-emerged this week, telling the Associated Press he was "really pleased" to return to work at his London-based private security firm, Orbis Business Intelligence.

"I'm now going to be focusing my efforts on supporting the broader interests of our company here," he said.

On Tuesday, Intelligence Committee Chairman Devin Nunes, R-Calif., announced the committee would hold its first hearing on Russia's election interference on March 20.

Nunes told reporters he had extended invitations to FBI Director James Comey, National Security Agency Director Mike Rogers, former CIA Director John Brennan, former Director of National Intelligence James Clapper and former acting Attorney General Sally Yates to testify.

While Nunes said he had not seen any evidence to prove Trump's allegations that President Barack Obama had Trump Tower wiretapped, he said the committee would look into the claims as part of the investigation. In particular, he said the Gang of Eight – the chairmen and ranking members of the House and Senate intelligence committees as well as the leaders in Congress, should have been made aware if Trump or his allies had been investigated.

Nunes said it was pertinent if intelligence officials felt they had reason to investigate any of Trump's inner circle.