(CNN) Paul Manafort, the former Trump campaign manager, turned over more than 300 pages of documents to the Senate intelligence committee related to its investigation of Russian election meddling, according to a source familiar with the Senate probe.

The documents included drafts of speeches, calendars and notes from his time on the campaign, the source said.

The committee had asked Manafort to provide materials documenting his ties to Russia.

Not included are details on Manafort's business ties in Ukraine, which the committee didn't ask for.

The FBI and Justice Department probe has focused in part on Manafort's businesses and financial ties in Ukraine. Manafort was a lobbyist working with the political party of former Ukrainian President Viktor Yanukovych, whose pro-Russian government was ousted in 2014. In recent months, he filed documents to retroactively register as a foreign agent to help resolve at least part of the Justice Department's probe.