WASHINGTON — In Friday’s indictment of Roger J. Stone Jr., a longtime informal adviser to President Trump, the special counsel for the first time revealed evidence of efforts by senior Trump campaign officials to learn how emails and other information that had been hacked by Russia and given to WikiLeaks could damage Hillary Clinton’s presidential campaign. The evidence appeared to contradict Mr. Stone’s assertions that he was acting on his own in his attempts to communicate with WikiLeaks. Senior campaign officials asked Mr. Stone to look into WikiLeaks’ plans, and he kept the campaign abreast of what he found out, the indictment said.

The special counsel, Robert S. Mueller III, disclosed new details about his investigation into Russia’s 2016 election interference and possible ties to the Trump campaign:

The campaign sought to learn how WikiLeaks’ releases might damage Mrs. Clinton

The public has long known that Mr. Stone and his associates had tried to connect with WikiLeaks in the summer of 2016 as Mr. Trump clinched the Republican nomination. Senior campaign officials dispatched Mr. Stone on that mission, the indictment revealed.

In June or July 2016, Mr. Stone told senior campaign aides that he knew that WikiLeaks had documents “whose release would be damaging to the Clinton campaign,” the indictment said. After WikiLeaks released emails stolen from the Democratic National Committee on July 22, 2016, “a senior Trump campaign official was directed to contact Stone about any additional releases” and other information that WikiLeaks had that could hurt Mr. Trump’s opponent in the race, Mrs. Clinton.

The Trump campaign officials were interested in learning about the stolen emails and other documents, despite the fact, as the indictment noted, that the Democratic National Committee had publicly blamed the Russian government more than a month earlier for hacking its computers.