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
It's going to be another dry day with plenty of sunny spells and feeling humid. Highs of 27 deg C.
A castle in Suffolk's hosted its first ever medieval jousting tournament as calls are made to make it an Olympic sport.
A mainly dry day with some sunny spells in the morning, but turning cloudier during the afternoon. Feeling warm. Highs of 27 deg C.