For 11 years, Anthony Templet was thought to be missing. Then he killed his own father.

At six years old, Anthony Templet vanished without a trace.

He was thought by his mother and half-sister to have been taken by his abusive father from the family’s Texas home, prompting a search that at more than a decade long, had started to feel futile.

Fast-forward 11 years, and the blonde-haired, blue-eyed little boy plastered over missing child posters suddenly reappeared. But the circumstances surrounding his reappearance are now the centre of a manslaughter case.

Anthony, now a teenager, is facing manslaughter charges for shooting his dad to death during an argument. He was found by his family only through his arrest.

According to the long-lost teen and his sister, he acted in self-defence against a man they describe as "evil".

The US 17-year-old, who was arrested earlier this month, confessed that he shot his father and alleged kidnapper, Burt, during an altercation.

The New York Post reports he told police the older man got drunk and initiated an argument which turned physical, so he grabbed two handguns, in case one failed to fire, and shot him three times in the head and torso.

Afterwards, he dialled 911, but Burt Templet died from his injuries days later.

According to Anthony, he was simply defending himself against his kidnapper, who had snatched him from his Houston home where he lived with his mother and half-sister Natasha.

His sister Natasha, who maintains her little brother acted in self-defence, recalled that Burt had been abusive to her mother when they lived together over a decade ago.

"When he was a baby, Burt would hold him in his arms while abusing my mother," Natasha said.

The allegedly abusive dad was charged with assault three times between 2001 and 2002, court records obtained by KHOU reveal, with two cases dismissed by a judge.

His wife filed for a protective order shortly before Burt vanished in his red Chevrolet Silverado pickup truck with Anthony in tow. He fled to Baton Rouge, where the young boy was home-schooled, and lived a "secretive life", according to neighbours.

In Baton Rouge, Burt Templet remarried, but the woman left him earlier this year, filing for a protective order against him in doing so. She posted on social media that Burt had allegedly knocked out several of her teeth.

Natasha, who spoke to Anthony over the phone from his prison for the first time since he went missing, called him "brave" for finally putting an end to his father's abuse.

She told WAFB: "After 11 years of waiting to hear if my brother was alive, he is found. My brave brother had to defend himself for the last time against that evil man."

"Burt and my mum were together for about ten years and it was extremely violent," she added, "I can only imagine what Anthony’s been through."

Natasha said her mum filed a custody case in a desperate bid to get Anthony back, but the case was dismissed.

She also said that she and her mother had posted "missing boy" flyers around Baton Rouge eleven years ago, rightly suspecting this was where Burt had taken him.

WAFB report, however, that there was no missing person report for Anthony listed with the National Crime Information Center (NCIC), according to the East Baton Rouge Parish Sheriff’s Office.

Natasha said Anthony sounded excited to reconnect with his sibling when she spoke to him from prison.

“I talked to him by phone yesterday for about 15 minutes,” she said. “It was great. He’s really sweet. We talked about things we did when he was younger.

“He asked if he remembered correctly a family vacation we took to Seattle. I could not believe he still remembered that trip. You could hear the smile in his voice,” she added.

Anthony was also able to talk to his mother, brother and 80-year-old grandmother by phone for the first time in 11 years.

Before his arrest, Anthony had started a job at a local plant nursery, according to neighbours.

But now, the teenager could see the manslaughter charges he faces upgraded to murder by a grand jury. They could, however, agree that he acted in self defence, freeing him to reconnect with his remaining relatives.

WAFB report that two Baton Rouge defence attorneys, Franz Borghardt and Jarrett Ambeau, have agreed to represent the 17-year-old for free.

A final decision on the teenager's fate is likely to take months, but for now, Anthony remains incarcerated at a juvenile facility in north Louisiana.