Inspectors from the Health and Safety Executive (HSE) are at the scene of an incident at the Royal estate at Sandringham.
A spokesman for the HSE said:
No formal investigation has been launched, but we do have inspectors at the scene with police who are making initial enquiries.
More top news
Heavy showers will move north during Saturday and it will feel cool. Sunday will be drier and brighter with long spells of sunshine.
A man who killed two young engineers who were on their way to work in a collision near Littleport has been jailed for five years.
The deaths of a man and a woman whose bodies were found on a mudbank are not being treated as suspicious.