Norfolk police has been handing out letters to photographers in Anmer warning against “acts of harassment”.
Photographers and film crews have been seen around Anmer and the Sandringham Estate since the Duke and Duchess of Cambridge arrived with Princess Charlotte and Prince George earlier this week.
The letter asked for “acts of harassment and breaches of privacy to cease”.
It said: “There have in the past been a number of intrusions into the privacy of the Royal Family which in the main have been as a result of professional photographers using long-distance lenses, not only to observe the Royal Family, but also to photograph them going about their activities on the estate.”
It added that the situation had improved after previous warnings to photographers.
The statement went on: “However, we would remind you again of the position.
“The Sandringham Estate trusts that there will not be a need to take any further action other than bringing these points to your attention.”
Kensington Palace also issued a statement to say that the “warm-hearted interest” with the Royal family needs to balanced with “their right to a private family life”.