Former Trump campaign chairman Paul Manafort visited Moscow at least 18 times over the last decade and was in regular communication with Russian President Vladimir Putin’s allies when he was a consultant in Russia and Ukraine for oligarchs and pro-Kremlin parties, according to a new report.

Flight records indicate Manafort’s visits to Russia were more frequent than previously believed, according to McClatchy.

Manafort also flew to Kiev 19 times in less than two years, even though Putin ally Viktor Yanukovych was no longer Ukraine’s president, as he worked for the pro-Russian Opposition Bloc party.

Manafort and his associate Rick Gates were indicted by a federal grand jury on Monday on 12 charges related to the work they completed in Ukraine, including conspiracy against the U.S., tax fraud, and money laundering. The indictments were the first to result from special counsel Robert Mueller’s investigation into Russian interference in the 2016 election and whether the Trump campaign colluded with the Kremlin.

Manafort and Gates pleaded not guilty at a federal courthouse hearing. Although the two men are under house arrest, a judge granted the men “limited release” for Thanksgiving, where they will be required to wear GPS devices and are prohibited from consuming alcohol.