For the last three years, RSPB Scotland has staged the Scottish Birdfair at Hopetoun House, west of South Queensferry. It has been occupied by Lord Hopetoun and his family for more than three centuries.
He also owns the 11,000-acre Leadhills grouse shooting estate in South Lanarkshire, which has one of Scotland's worst records for wildlife crime. More than 40 incidents have been reported since 2003, including convictions for laying poisoned bait and the shooting of an owl.
RSPB's use of Hopetoun House has prompted a series of angry attacks from bird-lovers, some of who boycotted the Birdfair. The RSPB, however, defended Lord Hopetoun, saying he did not condone illegal practices on his land and that there was a "clear separation" between Hopetoun House and Leadhills.
But now an activist website, Raptor Persecution Scotland, has reported that the RSPB is dropping Hopetoun House as the venue for next year's Birdfair. Sources have also told the Sunday Herald this is the case, saying a three-year contract with Hopetoun has ended.
Duncan Orr-Ewing, RSPB Scotland's head of species and land management, said: "We are indeed reviewing the location for the 2015 Scottish Birdfair and are deliberating over the future venue."
Hopetoun House, which describes itself as "Scotland's finest stately home", is owned by a charitable trust, of which Hopetoun - who was an executive with the former defence electronics company GEC Marconi - is a member. He lives in the house and runs the estate.
Leadhills has been on long-term lease to a sporting company registered in the US, and this is now up for renewal. In the past, Hopetoun has denied he was responsible for the management of the estate, though this has been disputed by land rights expert Andy Wightman.
Ronnie Graham, a member of the Dumfries and Galloway Raptor Study Group, who has campaigned against the use of Hopetoun House, said: "I'm delighted that RSPB Scotland has finally seen sense and cancelled Hopetoun House as the venue for the annual Scottish Birdfair.
"The links between Hopetoun House and the notorious Leadhills grouse moor are incontrovertible."
Keith Brockie, a wildlife artist in Aberfeldy who helped found the Scottish Raptor Study Group, withdrew from exhibiting at the Hopetoun event because of its relationship with Leadhills. "Hopefully, the RSPB will choose a more credible location for future fairs," he said.
A spokeswoman for Lord Hopetoun said that according to the RSPB, the Birdfairs at Hopetoun had attracted between 4000 and 6000 people. She added: "We have yet to hear whether the organisation will be staging their event at Hopetoun in 2015."