The special counsel Robert Mueller dropped a significant revelation in his list of questions for President Donald Trump.

According to the list, published this week by The New York Times, Mueller is interested in asking Trump about any efforts by the Trump campaign — including by his former campaign chairman, Paul Manafort — to reach out to Russia for help ahead of the 2016 US election.

Until now, news reports and testimony have indicated that any offers of assistance were on Russia's end.

The question suggests Mueller has evidence that members of the campaign, particularly Manafort, reached out to Russia or Russia-linked actors.

Thirteen of the 48 questions on the list deal with collusion.

The vast majority of the 48 questions the special counsel Robert Mueller wants to ask President Donald Trump in an interview have been public knowledge for some time, with one major exception.

Toward the end of the list, published on Monday by The New York Times, was this question: "What knowledge did you have of any outreach by your campaign, including by Paul Manafort, to Russia about potential assistance to the campaign?"

There has been no public indication, through news reports or testimony, that the Trump campaign reached out to Russia or Russia-linked actors for help ahead of the 2016 election. The offers of assistance — like a June 2016 Trump Tower meeting and communications involving the former Trump campaign aide George Papadopoulos — were all on Russia's end.

Mueller's inclusion of a question about outreach to Russia from the campaign's side — specifically from Manafort, the former campaign chairman — suggests he has information involving such an offer.

Manafort and Rick Gates, his longtime deputy, have been charged with dozens of counts related to financial crimes, conspiracy against the US, and failure to register as foreign agents.

While Manafort has maintained he is innocent, Gates pleaded guilty in February to two counts related to conspiracy and making false statements to the FBI. Experts said at the time that his plea deal indicated he had something of significant value to offer Mueller.

Gates also sat for a "Queen for a Day" interview with Mueller, during which a defendant answers any and all questions from investigators, including about their case and any other criminal activity they may have witnessed.

Mueller is digging deep into possible collusion

The question about outreach is one of 13 on the list related to possible coordination between the Trump campaign and Moscow around the 2016 election.

The rest of the questions largely focus on events involving Manafort; Roger Stone, the GOP strategist who was an informal adviser to Trump; Jared Kushner, Trump's son-in-law and senior adviser; and Michael Cohen, Trump's longtime personal lawyer.

President Donald Trump. Kevin Lamarque/Reuters

Mueller wants to know more from Trump about: