(CNN)House intelligence committee Chairman Devin Nunes detailed key pieces of his leaks investigation Thursday, arguing that the names of transition officials to President Donald Trump were sought by "Obama-era officials" in intelligence reports.
Devin Nunes details leak investigation, blames Obama officials
In a public letter to Director of National Intelligence Dan Coats, Nunes said that he plans to spend August drafting legislation that will help ensure prosecutions of officials who leak classified information.
"All leaks of classified information must be vigorously prosecuted, and the committee is working to ensure law, policy and funding are aligned to maximize the prosecution of these crimes," Nunes wrote.
Nunes also alleged in the letter that "Obama-era officials sought the identities of Trump transition officials within intelligence reports." He made the same charge in March after his clandestine trip to the White House, which ultimately led to him stepping aside from the Russia probe as he himself became the target of an investigation into whether Nunes leaked classified information.
The letter was signed only by Nunes -- no other members of the committee signed onto the request.
Nunes has been running a separate investigation from the House Russia investigation after stepping aside from leading the House's main Russia probe.
Thursday's letter marks the first time he has clearly outlined what he is searching for -- although he has given hints over the last few months, including issuing three subpoenas seeking information on three former Obama administration officials.
Members of the House Russia investigation, meanwhile, have also dug into leaks and the "unmasking" -- or privately revealing their identities in classified reports -- of names as part of the Russia probe. House intelligence committee members interviewed former Assistant Attorney General John Carlin, who oversaw surveillance programs for the Department of Justice, Thursday as part of the Russia probe.
The push by Nunes, who has shied from the national spotlight since stepping aside from running the House Russia probe, comes at the same time the White House has adopted an aggressive new stance toward leaks and fighting back against the Russia investigations.
Trump said he wants an aggressive pursuit of leaks of classified information -- leaks that have fueled increasingly damaging stories about his campaign's contacts with Russian officials last year. Attorney General Jeff Sessions, after a week in which he was publicly battered by Trump, is expected to announce he will increase efforts to find the source of these leaks.
And Trump's new White House communications director, Anthony Scaramucci, made an impression at the start of the week when he promised he would fire a press aide whom he alleged was behind leaks from the White House. But when news of Scaramucci's plan leaked to the press, the aide, Michael Short, resigned before Scaramucci could fire him.