Jeremy Vine says his stalker Alex Belfield has already put out a video saying he'll be back.
Belfield, a former local BBC radio presenter, was last week sentenced to five years in jail for masterminding an 11-month campaign of online harassment against Jeremy and other victims.
The 42-year-old targeted Jeremy and despite being behind bars, Vine claims he still has access to social media and claims he'll be 'back soon'.
As part of Belfield's barrage of hate, he shared Jeremy’s address online and urged his online followers to turn up at the star’s home.
The convicted stalker also made a series of slanderous videos that he shared on YouTube about Jeremy, and also sent aggressive emails to his former colleagues.
In a new interview on BBC Newsnight, Jeremy has branded Belfield's YouTube channel a "fountain of hate" as he opens up about the effects of his actions.
"I was afraid of what he could do to my family. I was afraid because you have to think around corners with this stuff," he said.
"And, you know, we've seen knife attacks on MPs, MPs being killed, people who are prominent being attacked. So I'm not trying to give myself undue status here, but I had to think this through."
Vine claims that Belfield had put out a video saying he was going to be back up and running.
According to the BBC, sentencing judge, Mr Justice Saini, told Belfield one of his victims had been "seconds away from taking his own life as a result of your conduct".
Vine told Newsnight he thought if the courts had not stopped Belfield "somebody would have died".
He said he feared that at some point one of the 400,000 people watching Belfield's videos "going to take a knife or acid to my home".
"The danger came from the online traffic, not from the individual," he said, adding Belfield wanted to "create so much hatred against me that someone acted by proxy".
Vine says he was forced to take it seriously as Belfield had already put his home address out.
"I've got two teenage daughters, you know, I can't be casual about it. So at that point I was scared for them," he added.
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