Prince William and Prince Harry have been keeping in contact with "informal" Zoom video calls.
The brothers are currently living halfway across the world from one another - Prince Harry in Los Angeles and Prince William in Norfolk - but they speak regularly online.
A source said: "William finds Zoom a good, informal way of keeping in touch, and some would say 'tabs', on his younger brother. There have been several zoom calls.
It's easy to set up and involves no awkward scheduling. After the children have gone to bed and supper with Kate. It has been only William and Harry. It is around lunchtime in LA. These calls are made from Anmer's private sitting room. It's not the room that Kate and William use for their public zoom sessions."
William and Harry have been keen to keep the calls between themselves to "take the pressure off".
A friend close to the royals told Fabulous magazine: "William is very anxious to keep the calls low key and casual. Just two brothers have a chat. No-one else is involved. It takes the pressure off. There is nothing formal about these zoom sessions. It's about keeping in touch that's important. Harry has spoken on Zoom to the Queen as well."
It comes after Prince William penned a letter on behalf of himself and his brother Prince Harry to their late mother Princess Diana's charity, The Diana Award.
Writing to the organisers, he shared: "I wanted to write to send my support and thanks to all the staff, volunteers and supporters of The Diana Award. My brother and I remain ever appreciative of the work you do to foster, develop and support young people, particularly at this time of uncertainty.
"Whilst you are finding yourselves adapting to new ways of working there is no doubt that your support for young people, through what will be anxious and unsettling times for many, is as important as ever. This comes with my very best wishes for good health to you and your families over the coming weeks."