(CNN) President Donald Trump's former national security adviser and Russia investigation cooperator Michael Flynn will be a "principal witness" in the upcoming trial of his former lobbying partner -- and his statements to special counsel Robert Mueller will matter in that case too, according to court submissions on Friday.
The flood of court requests from the lobbyist Bijan Kian made clear how much of the case will focus on Flynn. Kian's defense team wants every document it can get about the former Trump administration official as they prepare for trial.
Kian's legal team wants "all statements, transcripts, notes, records and memoranda" from federal prosecutors that reflate to anything Flynn said to "any agent, employee, representative or elected official" of the US government.
That includes investigators' memoranda of interviews Flynn gave to Mueller's legal team as they investigated the election and the Trump political operation.
Those notes -- especially about Flynn lying to Vice President Mike Pence and others in the early days of the Trump administration about his contact with Russia regarding sanctions -- could help Kian's lawyers cut into his credibility at trial, Kian's lawyers wrote. They've asked for the Mueller memos on Flynn but the Justice Department won't turn them over as potentially exculpatory material for Kian, the defense team wrote.
The court submissions on Friday also reveal just how long ago Flynn started helping the prosecutors with the Kian case. Prosecutors in the Eastern District of Virginia sought an interview and grand jury testimony from Flynn as early as June 2018, about six months after Mueller secured his guilty plea.
Kian, also known as Bijan Rafiekian, was charged with working illegally for the Turkish government in the US and pleaded not guilty in December. His trial is scheduled for July in the Eastern District of Virginia.
Flynn, Kian and another lobbying associate, the Istanbul-based businessman Kamil Ekim Alptekin, allegedly lobbied American politicians for the extradition of the Turkish cleric Fethullah Gulen, who lives in Pennsylvania. Alptekin hasn't appeared in US court to face his charges.
When Flynn admitted to lying to federal investigators about his contact with the Russian ambassador as part of the special counsel probe into 2016 election interference, he also admitted to lying to the Department of Justice about the work he did with Kian in their consulting company. Flynn agreed to cooperate with Mueller's team and other prosecutors in December 2017.
He has given them "substantial assistance" in criminal investigations, prosecutors have said. He has not yet been sentenced and continues to help prosecutors.
Kian's legal team also seeks documents from Flynn's lawyers at the law firm Covington & Burling, which worked on the foreign lobbying submissions Flynn's company made retroactively to the Justice Department before he was charged. The law firm still defends Flynn in his criminal case.
A spokesman for Covington & Burling declined to comment on Friday.