The father of missing Allan Bryant has received a death threat from a person claiming to have killed him.
A horrific message sent to Allan Bryant senior claimed that his son had been stabbed repeatedly and his body dumped in water and that he also would be stabbed.
It demanded £10,000 of reward money.
Police have launched an investigation into the communication, sent to Mr Bryant through Facebook, and have patrolled the Glenrothes street where he lives.
The Bryants, who have been searching for Allan Jr since he went missing after a night out in November 2013, have already been the victims of vicious trolling.
Mr Bryant believes another troll could be responsible but fears for his family’s safety following the latest threat, which he discovered on Saturday morning.
He said: “I’m not so worried about myself but I’m scared for my family.
“You don’t know what people are capable of.”
Mr Bryant said police had vowed to the catch the person behind the threat – understood to live in Fife – and had brought in their major investigation team to handle the inquiry.
He also said his home had been put on ‘red alert’ so that if he dials 999 he will get an immediate blue light response.
He said: “The police are treating this very, very seriously.”
The obscene message from a named sender said: “You sleep at night knowing we killed your son and knowing you can’t do anything about it.”
Mr Bryant said: “All we are trying to do is find out what has happened to Allan.
“This could be some sort of troll. We have already been hit by trolling in the past.
“How can people do something like this? You wonder what is going through their heads.”
He posted a video on Facebook warning the sender they would be found and imprisoned.
In it, he said: “We are going through a hard enough time as it is without Allan without sick individuals like this saying things like this about my son.
“This goes beyond trolling as I have been threatened to be stabbed and so have other people.
“Now we are living in constant fear that someone could come to our door.”
A Police Scotland spokesperson said: “We are aware of a threatening online communication that was sent to Mr Bryant.
“We have spoken to Mr Bryant and are investigating this to establish the full circumstances.”
The Bryants were sent a series of sick messages by Stewart McInroy claiming he had taken Allan Jr hostage and tortured and killed him.
McInroy, who also waged a campaign of abuse against his ex-girlfriend, was jailed in August 2014 for 10 months and appeared earlier this year on a BBC Three documentary about internet trolls.
Allan Jr was 23 when he disappeared after leaving the Styx nightclub in the early hours of the morning.
