One is the world’s most famous teenager, with £17million in the bank.

The other works part-time in an electronics store for £5 an hour, and relies on his mum to give him lifts to school.

Meet Miley Cyrus’s half-brother Christopher, 17, above.

Although there are just eight months between them and they share the same father, Miley and Christopher are worlds apart.

Days before the release of Hannah Montana: The Movie, Miley declared: “My priorities are my friends and my family.”

But she was referring to her dad Billy Ray Cyrus, mum Tish and siblings Brandi, Trace, Braison and Noah – she has never publicly mentioned the half-brother she has seen just five times in the past decade.

Recalling their last meeting at a Miley concert near his home in Fort Worth, Texas, in November 2007, Christopher said: “While she was on stage I was watching her from the sidelines.

“Afterwards we spent 20 minutes in her bus. Her voice is fantastic and I’m very proud of my sister.”

But behind the kind words and fondness for his superstar sister, the high-school student harbours bitter memories and regrets at missed opportunities.

Christopher was born after his mother, Kristin Luckey, had a brief relationship with musician Billy Ray Cyrus when she was a waitress in South Carolina. They had split by the time their son was born on April 8, 1992, and Billy Ray’s new girlfriend Tish was already pregnant with Miley.

Christopher is clearly disappointed he does not have a closer relationship with the Cyrus family and recalls being excluded from a reality show with them. “That kind of sucked,” he said.

Christopher believes he would be closer to Miley, 16, if he could get together with his father more often.

He reluctantly read out a string of text messages between him and his father, which began last Christmas Day with Christopher texting: “Merry Christmas.” He said he got a reply on January 4 from Billy Ray saying: “Hey bud, where you been? You disappeared on us.”

Christopher said: “I replied, ‘I disappeared? You disappeared. I tried to get a hold of you.’”

Billy Ray concentrates on the career of Miley, whose fame has eclipsed his own, which peaked with the 1992 single, Achy Breaky Heart. Miley, star of the hit TV series Hannah Montana, was a presenter at the recent Academy Awards and her concert tour last year grossed £37m.

She will publish her autobiography this spring and has an album at the top of the US pop charts. Showbiz experts say “Brand Miley” is worth $1billion (£670m) to Disney. In contrast, Christopher has more modest earnings. “I work at a store for $7.50 (£5.50) an hour. Sometimes I’ll get five hours a week, other weeks I’ll do 20. I take what I can get.”

But Christopher is generous when he talks about his sister. He said: “She doesn’t play the superstar in private. She’s a normal teenager having fun and she can laugh at herself.

“She’s the same now as she was before all this fame. She’s still my goofy sister. Miley is not a self-obsessed person at all. She’s just trying to have fun while working hard and I don’t know anyone who dislikes her.

“Miley asked how my mum was doing and was surprised that she had a little girl aged one and another on the way.”

Christopher’s eyes light up when he remembers the times they spent together as children at Billy Ray’s mansion near Nashville, Tennessee.

“She was always really outgoing and good to be around,” he said. “We used to play in the games room where there’s a pool table, jukebox, toys and gaming systems.”

While Billy Ray gave Miley a recording studio as a 16th birthday present, Christopher didn’t even get a phone call, card or gift from his natural dad on his birthday last month. Instead, he marked the occasion with his mum and stepdad Mark Sorine and his half-sister Ali, 12, at their home in a suburb of Fort Worth, Texas.

And its not the first time Billy Ray has forgotten his son, says Kristin, who is far more critical of the lack of contact between Christopher and the Cyrus family.

She said: “Chris reaches out to have a relationship but it’s been months since they engaged. Chris is a great kid and he handles it very, very well. He tried to keep a lot inside but I know when he’s hurting and really getting to him.”

Kristin recalled how she found out that Billy Ray was going to be a father with another woman.

“He went on TV and announced that he had a beautiful baby boy and another baby on the way.

“And that’s how I found out about Tish being pregnant with Miley. My jaw just dropped. There was a lot of anger in me but we kept talking. Then Billy Ray went on TV and said he and Tish were getting married and she was pregnant again.”

Kristin said that’s when communication between her and Billy Ray ended and “trickled away” for Christopher.

“No one acknowledges his birthday or even Christmas for him,” said Kristin, 39.

She said the multi-millionaire singer has always financially supported their son. Christopher, still hoping that he will get closer to Miley and his dad, added: “I’m on good terms but I don’t have a relationship with them really.”

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