York Minster has received "abusive" letters over a decision to support the reburial of Richard III in Leicester.
A campaign calling for the monarch to be reburied in York began after it emerged he would be reinterred in Leicester Cathedral.
The King had strong associations with Yorkshire, but the minster backed the plan in Leicester, where his remains were found underneath a car park.
The Minster said the letters would be investigated by its own security team.
In a statement, the cathedral said it had received a number of letters some of which had been abusive.
It continued: "These have been passed to the Minster Police, and they continue to monitor the situation closely."
Richard grew up at Middleham Castle in the Yorkshire Dales and visited York several times before his death at the Battle of Bosworth in 1485.
His remains were identified in February by a team from the University of Leicester.
Under the terms of the exhumation licence granted to the archaeologists the decision over the location of the king's reburial rests with the University of Leicester.
More than 25,000 people have signed a petition to support re-interring his remains in York Minster and York's MPs have urged a rethink.
But in February, the cathedral said it would not become involved in the argument and commended the King to "Leicester's care."
The current Dean of York, the Very Reverend Vivienne Faull, was previously Dean of Leicester.