Special counsel Robert Mueller’s investigation into President Donald Trump’s 2016 campaign has zeroed in on at least a dozen Ukrainian officials in politics and business who may have used Trump’s 2017 inauguration to advocate for pro-Russia policies and business deals, The New York Times reported Thursday.

According to the report, various officials attended big-ticket events hosted by Trump’s inauguration committee, using the opportunity to meet with Republican lawmakers and Trump allies, including by holding some meetings at Trump’s hotel in Washington. Several of the officials reportedly hoped to gauge how they could become influential in the eyes of the new administration, in order to boost issues favorable to Russia — such as lifting U.S. sanctions imposed after Russia’s seizure of Crimea — or land business deals.

Mueller and other federal prosecutors have opened inquiries into the officials, part of a larger thread of developments involving pro-Russian lobbying in Ukraine.

Former Trump campaign chairman Paul Manafort was convicted last year for crimes related to his work as a pro-Russian lobbyist in Ukraine. This week, Mueller’s investigation revealed in a court filing that it has accused Manafort of providing internal polling data from Trump’s campaign to suspected Russian intelligence operative Konstantin Kilimnik, another figure in Mueller’s investigation.