Spey Fishery Board said it has caused environmental damage.
It said this year’s salmon were upstream and survived the incident but many of last year’s stock are dead.
Duncan Ferguson, manager of Spey Fishery Board said: “The pollution has been two fly tipping incidents into the same drain on a lay-by within two hours of each other.”
The chairman for the Spey Fishery Board, Peter Graham, said: “This is heart breaking after all the hard work by our staff that has gone into trying to rejuvenate the river, only to see it damaged in this way by what appears to be fly tipping.”
Sepa urged anyone with information about the pollution incident to contact them by calling 0800 80 70 60 or getting in touch online, external.
