Plans to build a hydroelectric scheme on the Queen's Balmoral estate are facing a hurdle amid concerns they may not fit the aims of a national park.
The Cairngorms National Park Authority (CNPA), which is responsible for planning in the area, said the proposal raises "issues of significance to the collective aims of the National Park".
It has now called in the application from Aberdeenshire Council and will be the deciding body for the application.
Balmoral Estates proposes installing a 2MW hydroelectric scheme on the River Muick, approximately 7km to the south-west of Ballater.
The scheme comprises the construction of a buried pipeline approximately 3km long, a semi-buried powerhouse and a pipe and channel returning water to the river.
Aberdeenshire Council objected to the proposal citing noise concerns.
Team manager Louise Cunningham wrote: "I am concerned that there may be noise emission from the proposals which could be detrimental to the amenity of neighbouring noise-sensitive receptors.
"Typically hydropower turbines can emit significant amounts of noise."
She added: "The noise information currently provided in the Environmental Statement offers no measurements of the current background noise nor any site-specific predictions."
In its environmental statement in support of its application Balmoral Estates said that significant noise is not expected during either the construction or operational periods of the development.
Red squirrels, otters, badgers, water voles and pine martens are among the wildlife living in the area.
Balmoral Estates said that assuming mitigation and good practice measures are adopted "no significant residual impacts on terrestrial habitats have been predicted as a result of the proposed scheme".
Balmoral Estates can request the opportunity to address the planning committee in support of its application, and has until March 19 to ask to do so.
All planning applications in the national park area are made to the relevant local authority, but the CNPA "calls in" and determines the bigger and most sensitive applications.