Louis Tomlinson's father has threatened him with a family secret for attention

Los Angeles - Louis Tomlinson's estranged dad has threatened to drop a "bombshell".

The One Direction star's 46-year-old father, Troy Austin, hasn't spoken to Louis since they argued during a telephone call three years ago and now he has vowed to shake up his son's life if he continues to ignore him.

A source told the Sunday People newspaper: "Troy has always wanted to repair that relationship - but if Louis isn't prepared to do so, he's told a few friends he has something which would really throw a grenade into things.

"He sees it as his final shot at getting Louis's attention, and he's said he will drop the bombshell if he feels it's the only option he's got left, even though it would come as a massive shock.

"He knows it could cause another big rift within the family but is starting to feel he has nothing left to lose."

The threat comes almost a fortnight after it was revealed the 23-year-old musician is set to have a baby with his ex-girlfriend, Briana Jungwirth, with Troy previously revealing he hoped Louis would let him be a part of the tot's life.

He explained: "I'd like to be involved in my grandchild's life.

"I've missed out on Louis's life and I'd like to make up for that. It's definitely time to heal the rift. Life is too short."

Meanwhile Louis Tomlinson and Briana Jungworth reportedly have "real feelings" for each other.

The stud and his ex have been meeting up since the news that the American socialite is pregnant with his child - after a one night stand back in May - and the 23-year-old singer is spending "all his spare time" with the pretty blonde.

A source close to Briana said: "There are very real feelings there. It's not just about the baby.

"Louis is sacrificing all his spare time to see her. They spent last Sunday together after he made a whirlwind stop in LA during what was a rare day off for the band. And they spent the entire Fourth of July weekend together meeting each other's families."

A friend of the band confirmed reports that Louis and Briana - who is three months pregnant - are seeing a lot of each other but insisted they are not dating again.

They said: "Yes, they have hung out, but they're not in a relationship."