American spies collected information last summer revealing that senior Russian intelligence and political officials were discussing how to exert influence over Donald J. Trump through his advisers, according to three current and former American officials familiar with the intelligence, according to The New York Times.

The conversations focused on Paul Manafort, the Trump campaign chairman at the time, and Michael T. Flynn, a retired general who was advising Mr. Trump, the officials said. Both men had indirect ties to Russian officials, who appeared confident that each could be used to help shape Mr. Trump`s opinions on Russia, The New York Times wrote.

Some Russians boasted about how well they knew Mr. Flynn. Others discussed leveraging their ties to Viktor F. Yanukovych, the deposed president of Ukraine living in exile in Russia, who at one time had worked closely with Mr. Manafort.

The intelligence was among the clues — which also included information about direct communications between Mr. Trump`s advisers and Russian officials — that American officials received last year as they began investigating Russian attempts to disrupt the election and whether any of Mr. Trump`s associates were assisting Moscow in the effort. Details of the conversations, some of which have not been previously reported, add to an increasing understanding of the alarm inside the American government last year about the Russian disruption campaign.

The information collected last summer was considered credible enough for intelligence agencies to pass to the F.B.I., which during that period opened a counterintelligence investigation that is continuing. It is unclear, however, whether Russian officials actually tried to directly influence Mr. Manafort and Mr. Flynn. Both have denied any collusion with the Russian government on the campaign to disrupt the election.

John O. Brennan, the former director of the C.I.A., testified Tuesday about a tense period last year when he came to believe that President Vladimir V. Putin of Russia was trying to steer the outcome of the election. He said he saw intelligence suggesting that Russia wanted to use Trump campaign officials, wittingly or not, to help in that effort. He spoke vaguely about contacts between Trump associates and Russian officials, without giving names, saying they ”raised questions in my mind about whether Russia was able to gain the cooperation of those individuals.”

Whether the Russians worked directly with any Trump advisers is one of the central questions that federal investigators, now led by Robert S. Mueller III, the newly appointed special counsel, are seeking to answer. President Trump, for his part, has dismissed talk of Russian interference in the election as ”fake news,” insisting there was no contact between his campaign and Russian officials.

”If there ever was any effort by Russians to influence me, I was unaware, and they would have failed,” Mr. Manafort said in a statement. ”I did not collude with the Russians to influence the elections.”

The White House, F.B.I. and C.I.A. declined to comment. Mr. Flynn`s lawyer did not respond to an email seeking comment.

The current and former officials agreed to discuss the intelligence only on the condition of anonymity because much of it remains highly classified, and they could be prosecuted for disclosing it.

Before taking the helm of the Trump campaign last May, Mr. Manafort worked for more than a decade for Russian-leaning political organizations and people in Ukraine, including Mr. Yanukovych, the former president. Mr. Yanukovych was a close ally of Mr. Putin.

Mr. Manafort`s links to Ukraine led to his departure from the Trump campaign in August, after his name surfaced in secret ledgers showing millions in undisclosed payments from Mr. Yanukovych`s political party.

Russia views Ukraine as a buffer against the eastward expansion of NATO, and has supported separatists in their yearslong fight against the struggling democratic government in Kyiv.