Bruce Jenner's sex change has been planned for over a year.

Gossip website TMZ reports a leader in the transgender community has informed them they have known about the change for "way more than a year," well before he underwent a laryngal shave to reduce the size of his prominent Adam's apple.

Although the former athlete has yet to comment, a source close to the family previously revealed the star's six children - Burt, 36, Cassandra, 34, Brandon, 33 and Brody Jenner, 31, from previous relationships, and Kendall, 19, and Kylie Jenner, 17, from his marriage to Kris - just want him to be happy. They said: "The [kids'] concern seems to be Bruce's happiness, and he acts very pleased with his new life.

"It is an intense thing. Of course not everyone is 100 percent on board. Different people have different reactions. But everybody loves him."

The 65-year-old Olympian - who has sparked rumours of wanting to become a woman in the past by sporting colourful manicures, a ponytail and diamond stud earrings - is now believed to be feeling positive about himself, but is still keen to undergo the transition gradually.

A source close to the family added: "He's in such a great space. That's why he it's the perfect time to do something like this."