Phone records and intercepted calls show that members of Donald Trump‘s 2016 presidential campaign and his other associates had repeated contacts with senior Russian intelligence officials in the year prior to the election, officials said.

President-elect Trump and then-President Barack Obama were both briefed on details of the extensive communications between suspected Russian operatives and people associated with the Trump campaign and the Trump business, US officials familiar with the matter told CNN.

The communications were intercepted during routine intelligence collection targeting Russian officials and other Russian nationals known to US intelligence, the report said on Wednesday.

Among several senior Trump advisers regularly communicating with Russian nationals were then-campaign chairman Paul Manafort and then-adviser Michael Flynn.

Adding to US investigators’ concerns were intercepted communications between Russian officials before and after the US elections discussing their belief that they had special access to Trump, said two US law enforcement officials. The intercepted communications also included other associates of Trump, whom the officials declined to identify. On the Russian side, the contacts also included members of the government outside of the intelligence services, they said.

The call logs and intercepted communications were part of a larger trove of information that the Federal Bureau of Investigation (FBI) was sifting through as part of an investigation on the links between Trump’s associates and the Russian government, as well as the hacking of the Democratic National Committee computers, according to federal law enforcement officials.

Manafort denied that he was in contact with Russians known to US intelligence. “This is absurd,” he said.

“I have no idea what this is referring to. I have never knowingly spoken to Russian intelligence officers, and I have never been involved with anything to do with the Russian government or the (Vladimir) Putin administration or any other issues under investigation today,” he said.

Manafort, who has held business ties with Russian and Ukrainian individuals, also emphasized that his work for the Yanukovich government in Ukraine should not be interpreted as closeness to the Russians.

The intercepted calls are different from the wiretapped conversations in 2016 between Trump’s former National Security Adviser Michael T. Flynn and Sergey I. Kislyak, Russia‘s Ambassador to the US.

In those calls, which led to Flynn’s resignation on Monday night, the two men discussed sanctions that the Obama administration imposed on Russia in December.

On Tuesday, top Republican lawmakers said Flynn should be one focus of the investigation, and that he should be called to testify before Congress. Senator Mark Warner of Virginia, the top Democrat on the Intelligence Committee, said Flynn’s resignation would not stop the committee “from continuing to investigate General Flynn, or any other campaign official who may have had inappropriate and improper contacts with Russian officials prior to the election”.