The reward for information leading to the prosecution of those responsible for the killings in Ross-shire has topped £13,500.
The latest discovery near Conon Bridge brings the total to 13 red kites and four buzzards found in a two square mile area south east of the village.
Duncan Orr-Ewing, head of species and land management for RSPB Scotland, said: "Each confirmed death of these beautiful birds is yet another devastating blow for the vulnerable Black Isle population, which has been repeatedly hit by illegal poison use. The level of public anger and frustration over this is clear."
Over £3600 had been raised from public donations to the reward to boost the £5000 offered by RSPB Scotland and matched by an anonymous donor.