WASHINGTON — The expanding federal investigation into Russian interference in last year’s election is shining new light on the central role played by one member of Donald Trump’s inner circle — his son-in-law and top adviser, Jared Kushner — in reaching out to Moscow.

The latest disclosure — that, even before Trump took office, Kushner directed campaign foreign policy adviser Michael Flynn to reach out to Russia in an effort to quash a United Nations resolution — is one of numerous Kushner contacts with Moscow and meetings with Russian intermediaries now under scrutiny by special counsel Robert Mueller.

Kushner, a 36-year-old former Manhattan real estate developer, may be key as Mueller pursues the mystery of whether Trump’s campaign had improper dealings with Russia, a charge that Kushner denies.

Revelations about Kushner’s Russia contacts have been dribbling out for the months, forcing Kushner and other Trump aides who denied or downplayed them to repeatedly backtrack.

But with Flynn now cooperating with Mueller’s investigators, Kushner’s role as handling outreach to foreign governments for Trump is likely to get even more scrutiny from investigators. Flynn pleaded guilty Friday to lying to the FBI about his own Russia contacts.

Trump publicly insists he is not worried, telling reporters Saturday there was “absolutely no collusion” with Moscow, but adding, “We’ll see what happens.”

In the wake of Flynn’s plea deal, Democrats on both the House and Senate intelligence committees said they want Kushner, who appeared in private before both panels in July, to return to answer new questions about his dealings with Russian officials and intermediaries from Moscow.

“Mike Flynn wasn’t acting as a free agent. He was acting at the behest of very senior people close to the president or the president himself,” said Rep. Adam Schiff, D-Calif., the top Democrat on the House intelligence committee. “If Mr. Kushner was involved in that, he’d have a lot (to) tell us that he hasn’t told us so far.”

Kushner’s lawyer, Abbe Lowell, declined to comment on Kushner’s Russia contacts.

Kushner has described himself as an overworked and inexperienced campaign aide who was “forced to make changes on the fly” when it came to Russia.

“I did not collude with Russia, nor do I know of anyone else in the campaign who did so,” Kushner said in July after a closed-door meeting with investigators from the Senate Intelligence Committee.

Trump cycled through a cadre of high-level aides during the presidential campaign, but Kushner remained a trusted adviser with one particularly unassailable credential — he is married to Trump’s elder daughter, Ivanka Trump.

After Trump won the White House, Kushner joined the administration and received a vast portfolio of responsibilities, including overhauling the federal government and pursuing peace between Israelis and Palestinians.

He has insisted that his initial failure to report his meetings with the Russians or any other foreigners on forms required for a government security clearance was not deliberate.

According to court papers disclosed Friday, Flynn was directed by a “very senior member” of Trump’s transition team — identified by a former official as Kushner — to lobby Russian Ambassador Sergey Kislyak and officials from other foreign governments in an attempt to delay or defeat a United Nations Security Council resolution critical of Israel in December 2016.

Trump had publicly opposed the resolution, saying it “puts Israel in a very poor negotiating position.”

But the Trump administration’s attempt to block the resolution was at odds with that of the Obama administration, which still occupied the White House and planned to let the resolution pass.

The attempt to influence the vote, which a person familiar with the transition efforts described as a collaborative endeavor by multiple high-ranking members of Trump’s team, did not succeed. Kislyak said Russia would not vote against the resolution, which passed after the United States abstained.

Earlier that month, at a meeting at Trump Tower in New York, Kislyak asked Kushner whether the Trump transition office had a secure phone line that Trump’s aides could use to talk to Russian generals about the war in Syria.

Because none was available, Kushner said he asked about using one at the Russian embassy.

He said that after Kislyak told him that was impossible, they agreed to follow up after the inauguration.

In contrast to Flynn, who admitted that he and Kislyak had discussed U.S. sanctions imposed on Russia by the Obama administration, Kushner has said that he did not discuss lifting U.S. sanctions that the Obama administration imposed on Russia in 2014 after Vladimir Putin’s government annexed Crimea.

In testimony to Congress last summer, Kushner also denied having any contact with WikiLeaks during the campaign, according to a statement from his lawyer.

WikiLeaks was responsible for releasing hacked emails that U.S. intelligence agencies say were obtained through Russia’s attempt to interfere with the presidential election.

But Kushner was forced to backtrack when The Atlantic magazine revealed last month that the president’s eldest son, Donald Trump Jr., forwarded a message from WikiLeaks to Kushner and others.

Kushner also attended a June 9, 2016, meeting in Trump Tower with Natalia Veselnitskaya, a Russian attorney introduced to Trump Jr. as “a Russian government attorney” who was part of “its government’s support for Mr. Trump.”

david.cloud@latimes.com