THE family of Dáithí Mac Gabhann, who have been at the forefront of a successful campaign to reform Northern Ireland's organ donation law, have told of how they have been left "extremely disappointed" after hate mail was sent to them.
Police said they are treating the anonymous, handwritten letter, which contained "sectarian remarks", as a hate incident.
The letter was sent to the family's home in Ballymurphy in west Belfast on Wednesday just weeks after they celebrated the successful passing of Dáithí’s Law at Westminster.
Dáithí’s Law is named after the six-year-old who has been waiting for his transplant for most of his life after he was born with hypoplastic left heart syndrome.
The opt-out organ donation system, which will take affect in June, means all adults became potential donors unless they specifically opt out.
Dáithí’s parents Máirtín and Seph had campaigned tirelessly for the move.
The MacGabhann family described the letter as "hateful".
In a statement, the family said: "We are extremely disappointed to receive a hateful handwritten anonymous letter in the post today.
"Our family and campaign will not tolerate such behaviour and if it continues, further action will be taken".
A PSNI spokesman said: "The letter contained sectarian remarks and is being dealt with as a hate incident.
"The recipients of the letter have received appropriate advice from local police".