Funding for the National Trust for Scotland's (NTS) Mar Lodge Estate near Braemar has been suspended amid shooting fears.
Subsidised grouse and deer shooting was a concern raised
Scottish Natural Heritage (SNH) said it was worried the money - more than £2m over five years - may be used to subsidise grouse and deer shooting.
SNH said funding was being withheld pending further reassurance it would be used for conservation work.
NTS has previously insisted the subsidy would be ring-fenced for conservation.
It followed concerns raised by animal rights campaigners.
SNH chairman, Andrew Thin, told BBC Scotland that the board wanted to be satisfied that the money would be used for conservation, and that public money would not used for grouse and deer shooting.
He added: "Marr Lodge is of national importance."
An NTS spokesman said: "We are awaiting official confirmation from Scottish Natural Heritage regarding their latest position on the proposed management agreement for Mar Lodge Estate.
"However, we look forward to working with SNH to provide clarification and reassurance on any issues or concerns they may have."