WASHINGTON — Former Vice President Mike Pence has been subpoenaed by the special counsel investigating former President Donald Trump’s effort to stay in office after the 2020 election and his role in the Jan. 6 attack on the Capitol, according to a source familiar with the matter.

Special counsel Jack Smith was appointed in November by Attorney General Merrick Garland to lead the Justice Department’s inquiries into Trump’s role in the riot as well as the former president’s handling of classified documents after he left office. The subpoena is related to the Jan. 6 investigation, the source said.

Spokespersons for Smith and Pence declined to comment on the matter.

ABC News first reported that Pence has been subpoenaed.

In December, NBC News reported that Smith had subpoenaed local officials in key presidential swing states for any and all communications involving Trump, his campaign and a series of aides and allies who assisted in his effort to overturn the 2020 election.

The move was an indication that Smith is probing into a scheme involving fake electors, a slate of individuals who signed documents purporting they were their states’ rightful electors and falsely asserting Trump was the victor in those states.

The House committee formed to investigate the attack on the Capitol gathered evidence that the fake electors submitted false certifications of Trump victories to the National Archives in hopes of having Pence substitute them for the actual electoral votes that made Joe Biden president.

The Jan. 6 committee devoted an entire hearing to Pence’s role on that day — and the intense public and private pressure Trump applied to Pence to get his vice president to interfere with the electoral count.

Pence, as then-president of the Senate, presided over Congress’ certification of the 2020 election results, but that role was strictly ceremonial, with no power to intervene in the counting of electoral votes.

Still, Trump sought to apply pressure on his vice president even after Pence’s aides, as well as Trump’s, said it would be illegal for the then-vice president to interfere in the count, according to testimony before the Jan. 6 committee.