The Whyte Crane Hire vehicle was left balancing on its side with its wheels in the air at Peterhead Business Park yesterday afternoon.
No-one was believed to have been operating the crane when the incident happened near the town harbour in Aberdeenshire.
It was thought to have been used by subsea engineering firm Aquatic to load equipment on to a low loader.
A company spokeswoman said no-one was injured yesterday.
She said: "Aquatic, an Acteon company, is investigating reports of an incident at our Peterhead facility.
"Our senior leadership team has launched an investigation."
The subsea firm specialises in laying and lifting equipment and cables from the seabed for oil and gas firms.