The TV presenter and naturalist, 60, was targeted in October last year, when people set a Land Rover on fire outside the gate of his New Forest home.
Speaking about the scary incident on the BBC's Crimewatch Live, he said: “Myself and the dogs went to bed, rather early for us, at just before midnight, and then shortly after 12.30am there was an enormous explosion.
“That was the first I knew of the incident. The car had clearly exploded. The bang was tremendous, the dogs flew off of the bed and started yelping and barking straight away.”
Tomorrow I'll be speaking on @BBCCrimewatch on @BBCOne at 10 am about the firebomb attack on my home last October . DI Howard Broadribb CID from the superb @HantsPolice will reveal new evidence . If anyone has any information please call 101 quoting incident reference 44210403698 pic.twitter.com/89O5kwM7VZ
— Chris Packham (@ChrisGPackham) March 15, 2022
Packham went on: “Where I live, we’re not prone to any loud interruptive noises at night so it was quite startling. And then, of course, it came to pass that this vehicle had been parked outside the gate and was ablaze.”
The star said the fire service and police attended and put out the blaze.
He said the fire destroyed the gate and damaged an old tree.
“The car was completely burned out," he explained.
"It got so hot that the engine lock had melted, so it was quite an explosion.”
After the incident last year, Packham said he had received threats in the past because of his advocacy for wildlife.
He tweeted: “If you think that by burning down those gates, I'm suddenly going to become a supporter of unsustainable illegal shooting, the unwarranted savagery wrought upon foxes in our countryside when they're torn to pieces by dogs, then you're wrong.
"I will, of course, just carry on because I have no choice.
"I cannot and will not let your intimidation sway me from my cause, and that's why I don't really understand why you would do it."
Packham tweeted a picture of the blaze this week.
He asked anyone with information to call 101 quoting incident reference 44210403698.
Watch: Chris Packham: We've all got to play our part to protect wildlife