Conservationists have expressed concern for the young male bird, whose whereabouts has been unknown since communications were lost in December.
They fear the two-year-old could have been illegally killed as his last recorded location was in the northern Monadhliath mountains in Inverness-shire, an area where a number of other birds have vanished over the past seven years.
Data from the transmitter showed he had been living in upland region north of Tomatin since early last year.
He had stayed almost exclusively in this area, which is home to grouse shooting moors, until his tag stopped broadcasting.
The latest report comes shortly after it emerged that a tagged golden eagle known as Fred was lost in similar circumstances on the outskirts of Edinburgh.
A police investigation has been launched but no further clues have so far been found.
A report commissioned by the Scottish Government found 41 out of 131 satellite-tagged golden eagles disappeared in “suspicious circumstances” in the Highlands during a 12-year period, with the majority of incidents occurring over land managed for driven grouse shooting.
Duncan Orr-Ewing, head of species and land management for RSPB Scotland, said: “This is now the 12th tagged eagle to go missing in this black hole in just seven years, and is entirely consistent with the systematic and ongoing illegal persecution of eagles in this area.”
He added: “In parts of the Monadhliaths, such as the area from where this bird fledged, golden eagles are doing well, but the efforts by some landowners, farmers and gamekeepers to protect these magnificent birds are constantly being undermined by persecution when eagles move out of these safe areas.
“There can be little doubt that current legislation and enforcement have proven to be insufficient deterrents to those criminals, invariably linked to the management of driven grouse shooting, who are intent on killing protected birds of prey.”
But gamekeepers and estate owners have hit back, claiming accusations of illegal persecution are premature and should be substantiated.
“Yet again we see RSPB acting unilaterally as judge and jury without waiting for those professional experts in the police and the procurator fiscal’s office to reach an informed decision as to the actual facts,” said David Johnstone, chairman of Scottish Land & Estates.
“We believe this continual smearing of grouse moors actually runs the risk of being counterproductive and directly impacting all the good, productive collaboration that has taken place in recent years.
“Incidents such as this absolutely do need to be investigated but it is for Police Scotland to lead investigations. They have very extensive powers to gather evidence as they see fit, and we would expect all our members to assist them in their enquiries.”
A spokesman for the Scottish Gamekeepers Association added: “The public deserve to see the hard evidence which exists that the lost signal was down to grouse management and not any other cause, such as a faltering tag, natural mortality, eagles fighting over territory or any of the other land uses in the broad general area which include farming, forestry and wind energy.”
Anyone with information about the eagle’s disappearance is being urged to contact Police Scotland.