WASHINGTON (Reuters) - The U.S. Senate Intelligence Committee has subpoenaed one of the president’s sons, Donald Trump Jr., to answer questions about his contacts with Russia, two congressional sources said on Wednesday.

The panel, which along with the Senate is controlled by Trump’s fellow Republicans, wants to question Trump Jr. about testimony he gave to the Senate Judiciary Committee in September 2017 which was subsequently contradicted in public testimony by former Trump attorney Michael Cohen, one of the sources said.

The committee is one of the few in the Senate that has been conducting serious investigations related to Russian meddling in the 2016 U.S. presidential election. Trump’s son-in-law and adviser Jared Kushner has appeared before the panel at least twice.

During his Judiciary Committee appearance, the source said, Trump Jr. was asked about the extent of his involvement in a plan to build a Trump Tower in Moscow.

“Like I said, I was peripherally aware of it, but most of my knowledge has been gained since as it relates to hearing about it over the last few weeks,” Trump Jr. told the committee, according to an official transcript.

In testimony before the House of Representatives Oversight Committee, however, Cohen, said he briefed Trump family members “approximately 10 times” about the Moscow Trump Tower project, and that Trump Jr. and his sister Ivanka were among the family members he briefed.

Cohen has also told Congress that some reimbursement checks issued to him for hush money payments to an adult film star who said she had an affair with President Trump were signed by Trump Jr, as well as the Trump Organization’s chief financial officer.

FILE PHOTO: Donald Trump Jr. speaks on stage during a rally for U.S. President Donald Trump at El Paso County Coliseum in El Paso, Texas, U.S., February 11, 2019. REUTERS/Leah Millis

Cohen this week began serving a federal prison sentence for

tax evasion and campaign finance violations.

In his report on Russian meddling in the U.S. presidential election in 2016, Special Counsel Robert Mueller’s team of prosecutors reported that there was a “reasonable argument” that Trump Jr. violated campaign finance laws.

But Mueller’s team concluded they did not believe they could obtain a conviction.

A lawyer for Trump Jr. did not immediately respond to a request for comment on Wednesday.

A Senate Intelligence Committee spokeswoman declined to discuss details of its own long-running investigation into Russia’s election interference.

Along with senior campaign adviser Paul Manafort and Trump’s son-in-law Jared Kushner, Trump Jr. participated in a June 2016 meeting at Trump Tower with Natalia Veselnitskaya, a Russian lawyer who they believed had damaging information on Hillary Clinton, Trump’s Democratic opponent in the election.

At one point, Trump Jr. sent Rob Goldstone, a publicist involved in setting up the meeting, an email declaring: “If it’s what you say, I love it ...”

But he later tweeted that all Veselnitskaya wanted to talk about was adoption policy and an anti-Russian U.S. sanctions law.

In his report, Mueller detailed extensive contacts between Trump’s election campaign and Russian operatives, but did not find evidence of a conspiracy.

Trump Jr. has used his Twitter feed to condemn the investigations and media coverage of his father, tweeting on Wednesday: “Democrats are not interested in the truth, they just want to keep the Hoax going forever. The games need to stop.”

“Investigate the investigators!” he tweeted on Tuesday.