His father Keith, 50, branded him "idiotic" and said the whole family had been disappointed by his behaviour.
But he questioned whether it was right to hold the teenager.
"He has been stupid but it's totally out of order to arrest him over one complaint," he said. "I would have preferred if they had come, taken him to the police station and told him off.
"We've been told he cannot stay at ours and should go to relatives or friends in case people are out there wanting to carry out reprisal attacks. That's the advice of the police. We've had loads of phone calls from people who are angry and outraged."
He said his son had got very drunk at a party before he posted the picture: "He was woken up by a phone call from one of my mates telling him to remove it. He couldn't remember putting it up.
"He deleted it as soon as he realised. The next thing we know is that he has been arrested."
House was arrested under the Malicious Communications Act, which carries a maximum sentence of six months in jail and/or a £5,000 fine. His grandmother Valerie said: "He's been an idiot while drunk but the police have gone over the top on this one."
The family from Aylesham near Canterbury has the support of civil liberties groups, which claim the arrest is an infringement of free speech.
Nick Pickles, from pressure group Big Brother Watch, said: "It is not illegal to offend people and, however idiotic or insensitive the picture may have been, it is certainly not worthy of arrest."
"The case highlights the urgent need to reform a law that poses a serious risk to freedom of speech." Agnes Callamard, of the Article 19 campaign group, said: "Causing offence, showing poor judgment or expressing views which people find to be in bad taste should not amount to criminal prosecution."
But war veterans and community leaders reacted with disgust at the poppy-burning stunt.
"It's absolutely disgusting and disgraceful what this lad allegedly did," said Granville Cosier, a local councillor and ex-serviceman. "I'm sure any right-minded person would agree with me that whoever did it should be dealt with and severely punished.
"Even if he says he was drunk or under the influence of drugs, it doesn't excuse what was done."
Bob Thompson, another local councillor, said: "The image on the internet has cast a dark shadow over Remembrance Day."
House is on a practical environmental studies building course and is a member of the Snowdown Colliery Rugby Football Club where his father is club captain.
Kent Police said yesterday: "Following an investigation, a 19-year-old Canterbury man was arrested on suspicion of an offence under the Malicious Communications Act."
In March last year, Emdadur Choudhury, of Muslims Against Crusades, was fined £50 for burning replica poppies on Armistice Day. Convictions for internet abuse have more than doubled in the space of five years, alongside the enormous growth in social media sites.
The number has grown from 498 in 2007 to 1286 in 2011.
- DAILY MAIL
