Gold medallist Usain Bolt stands on the podium during the medal ceremony for the Men's 4x100m final during the athletics at the Rio 2016 Olympic Games. Picture: AFP

Shoba RaoNews Corp Australia Network

USAIN Bolt’s sister has revealed details about his relationship with girlfriend Kasi Bennett, who she believes is perfectly suited to marry him.

Christine Bolt-Hylton, 32, told The Sun that her brother Usain had kept his relationship with Jamaican woman Kasi Bennett a secret before he recently confirmed they had been dating for two years.

But she confirmed that Usain, who just turned 30, and Kasi, 26, have been dating for three years.

Christine said she had met Kasi, and said she thought it was possible Usain would propose to her when he gets home from the Rio Olympic Games.

“I’ve met her and she’s lovely — she’s perfect for Usain,” she told The Sun.

“I would say that there’s a very strong possibility they’ll get engaged when he comes home.”

After seeing them together at Usain’s restaurant in Jamaica, Christine also said she thought Kasi was “the one” girl for Usain.

“They like the same music, the same food and doing the same things together and it makes sense for them to get together,” she told The Sun.

A photo posted by Kasi J. Bennett (@kasi.b) on

She also said Usain has expressed interest in starting a family on day, and that Kasi was one of few women he had been in a “serious”relationship with for a long time.

“I’ve talked to Usain about starting a family and he says he wants to, and I’m sure he will now he’s achieved so much,” she said.

“Usain has had a few girlfriends, but not many — but no one ever as serious as Kasi and I’m sure he’ll be settling down with her before long.

“I think she’s the one.”

Bolt’s Jamaican girlfriend sent the internet into a frenzy after she began posting messages of support to him during the Olympic Games on her social media accounts.

Bolt recently referred to them as “President and First Lady” in a photo he posted on Instagram.

President And First Lady 🙌🏾

A photo posted by Usain St.Leo Bolt (@usainbolt) on

Bennett is prolific on social media with her support for Bolt and her passion for fashion and selfies she shares with more than 30,000 of her followers on her Instagram account.

A photo posted by Kasi J. Bennett (@kasi.b) on

A photo posted by Kasi J. Bennett (@kasi.b) on

A photo posted by Kasi J. Bennett (@kasi.b) on

A video posted by Kasi J. Bennett (@kasi.b) on

A photo posted by Kasi J. Bennett (@kasi.b) on

After Bolt convincingly won his triple-triple gold medal haul, leading Jamaica to the gold medal in the men’s 4x100m relay, Bennett posted on her Instagram: “Respect the legend”.

Respect the legend🏅🏅🏅

A photo posted by Kasi J. Bennett (@kasi.b) on

Just days ago, she posted that Bolt’s success story at the Rio Olympics had already written. “Time to publish”, she wrote on Instagram.

The story is already written. Time to publish ⚡#LEGEND

A photo posted by Kasi J. Bennett (@kasi.b) on

On Twitter, she also described him affectionately as “My Boss” and “My babbbbbbbbbbbyyyyyyyyyyy!!!”.