WASHINGTON, May 8 (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 is seeking to question Trump Jr. about congressional testimony he gave in September 2017 to the Senate Judiciary Committee which was subsequently contradicted in public testimony by former Trump attorney Michael Cohen, one of the sources said.

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, who began serving a federal prison sentence earlier this week, said he briefed Trump family members “approximately 10 times” about the Moscow Trump Tower project, and that Donald Junior and his sister Ivanka were among the family members he briefed.

A Senate Intelligence Committee spokeswoman declined to discuss details of its long-running investigation into allegations of Russian meddling in the 2016 U.S. presidential election.

A lawyer for Donald Trump Jr. did not immediately respond to a request for comment. (Reporting by Mark Hosenball; Editing by David Alexander, Chris Reese and James Dalgleish)