The Duke of Sussex is "aware of everything that is happening" in the investigation into how the BBC secured an interview with his mother in 1995.
"You do not need a public statement to imagine how he is feeling privately," a source close to Prince Harry said.
The BBC has promised to "get to the truth" about the events surrounding the Panorama interview with Princess Diana.
But her brother, Earl Spencer, has said he is not "satisfied" with the parameters set around the inquiry.
The source close to Prince Harry was responding to suggestions the prince had failed to speak up over the controversy surrounding the Panorama interview.
In the past few days some newspapers have carried criticism of Prince Harry for not "standing by" his brother, the Duke of Cambridge.
It comes after Prince William said the investigation was "a step in the right direction" in a statement released by Kensington Palace on Thursday.
"Harry is getting regular updates and is aware of everything that is happening," the source told the BBC.
"You do not need a public statement to imagine how he is feeling privately, people know how much his mother means to him.
"He has bravely spoken out in the past about loss and grief, and the immense impact it has had on him.
"Sadly, some people are not just seeing this as a drive for truth, but also trying to use this as an opportunity to try to drive a wedge between the brothers."
An investigation was launched following claims by Diana's brother that the BBC's Martin Bashir used forged bank statements to convince her to do the interview.
On Wednesday, the BBC announced that Lord Dyson, one of the country's most senior retired judges and a former Supreme Court judge, had been appointed to lead the inquiry.