Plans to build a hydroelectric scheme on the Queen's Balmoral estate are to come under scrutiny from park chiefs 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 which was originally submitted to 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.
"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 the application, Balmoral Estates said 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.
In the environmental statement Balmoral Estates said, 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, which in this case was Aberdeenshire Council, but the CNPA "calls in" and determines the bigger and most sensitive applications.
CNPA regularly calls in hydro plans and said its policies generally encourage renewable energy of a scale and character that is compatible with the National Park, particularly biomass and hydro.
A park authority spokeswoman said: "The CNPA planning team take an objective and professional approach to all cases based on the merits of the submission and the prevailing policy context."
Balmoral Estates did not wish to comment on the application.