According to East Lothian Animal Rescue and Advice (ELARA), the mammal was "found to be deceased and in a state of decay” on a beach near Port Seton.
In a statement, the ELARA said: “A small beaked whale has washed up on the beach at Port Seton.
“Unfortunately it was already found to be deceased and in a state of decay.
“The BDMLR, the Scottish Strandings scheme and Easy Lothian countryside Rangers have all been made aware, and measures are underway to deal with the body.
“We would please ask members of the community to keep all dogs on leads when on the beach and to keep a respectful distance from the animal until it is properly dealt with by the appropriate agencies.”
The ELARA added that a post mortem may be required, and any exterior interference may hinder those efforts.