Justin Hemmes, 48, steps out with his model girlfriend Madeline Holtznagel, 25, in Byron Bay

Justin Hemmes is still going strong with his model girlfriend, Madeline Holtznagel.

The 48-year-old billionaire businessman was spotted enjoying a stroll with his much younger girlfriend in Byron Bay on Monday.

Justin and Madeline, 25, were joined by the mogul’s two young daughters, Alexa and Saachi, who he shares with his ex, Kate Fowler.

Still together: Justin Hemmes is still going strong with his model girlfriend, Madeline Holtznagel

The couple appeared happy on the outing, smiling affectionately at one another as they walked alongside each other.

They kept pace with Alexa, four, and Saachi, three, who pedalled nearby on their bicycles for most of the outing. 

At one stage, one of the little girls became tired, with Justin carrying her the rest of the way, as Madeline carried her bicycle. 

The look of love: The 48-year-old billionaire businessman was spotted enjoying a stroll with his much younger girlfriend in Byron Bay on Monday

The look of love: The 48-year-old billionaire businessman was spotted enjoying a stroll with his much younger girlfriend in Byron Bay on Monday

Family outing: Justin and Madeline, 25, were joined by the mogul's two young daughters, Alexa and Saachi, who he shares with his ex, Kate Fowler

Family outing: Justin and Madeline, 25, were joined by the mogul’s two young daughters, Alexa and Saachi, who he shares with his ex, Kate Fowler

Ride on: They kept pace with Alexa, four, and Saachi, three, who pedalled nearby on their bicycles for most of the outing

Ride on: They kept pace with Alexa, four, and Saachi, three, who pedalled nearby on their bicycles for most of the outing

Justin kept a watchful eye on his young daughters as they rode on the road beside him.

They appear to be riding out Sydney’s current COVID lockdown in Byron Bay, which hasn’t been as adversely affected. 

The owner of multiple pubs, hotels, restaurants and bars looked stylish in a pair of beige linen pants.

Keeping their distance: They appear to be riding out Sydney's current COVID lockdown in Byron Bay, which hasn't been as adversely affected

Keeping their distance: They appear to be riding out Sydney’s current COVID lockdown in Byron Bay, which hasn’t been as adversely affected

Heavy lifting: At one stage, one of the little girls became tired, with Justin carrying her the rest of the way, as Madeline carried her bicycle

Heavy lifting: At one stage, one of the little girls became tired, with Justin carrying her the rest of the way, as Madeline carried her bicycle

Keeping it casual: The owner of multiple pubs, hotels, restaurants and bars looked stylish in a pair of beige linen pants

Good jeans: Madeline looked chic in a blue denim jumpsuit, which was belted at the waist

Keeping it casual: The owner of multiple pubs, hotels, restaurants and bars looked stylish in a pair of beige linen pants

He also wore a salmon-coloured T-shirt and a peach-coloured sweatshirt was knotted around his shoulders.

Justin rounded out his ensemble with a pair of white sneakers, and eventually tied his unruly blonde hair back in a ponytail.

Meanwhile, Madeline looked chic in a blue denim jumpsuit, which was belted at the waist.

Secret romance: Speaking to The Sydney Morning Herald in October, Madeline said they'd actually met two years before reports emerged of their relationship early last year

Secret romance: Speaking to The Sydney Morning Herald in October, Madeline said they’d actually met two years before reports emerged of their relationship early last year

'We have known each other for two years and met when I was modelling in Singapore,' Madeline said in October of her relationship with Justin

Moving in: It was also reported that Madeline was living in a penthouse apartment owned by Justin in the Sydney beachside suburb of Coogee

‘We have known each other for two years and met when I was modelling in Singapore,’ Madeline said in October of her relationship with Justin

Pretty in pink: She also wore white sneakers and carried a pale pink handbag on one of her shoulders

Pretty in pink: She also wore white sneakers and carried a pale pink handbag on one of her shoulders

She also wore white sneakers and carried a pale pink handbag on one of her shoulders.

The Wollongong-raised model rounded out her ensemble with a pair of black Prada sunglasses, and her blonde hair was worn braided in a high ponytail.

While it’s not known exactly how long Justin and Madeline have been dating, she hinted their relationship has carried on longer than many people expect.

Perfect match: Justin wore a salmon-coloured T-shirt and a peach-coloured sweatshirt was knotted around his shoulders

Perfect match: Justin wore a salmon-coloured T-shirt and a peach-coloured sweatshirt was knotted around his shoulders

Braidy bunch: The Wollongong-raised model rounded out her ensemble with a pair of black Prada sunglasses, and her blonde hair was worn braided in a high ponytail

Tied up: Justin rounded out his ensemble with a pair of white sneakers, and eventually tied his unruly blonde hair back in a ponytail

Braidy bunch: The Wollongong-raised model rounded out her ensemble with a pair of black Prada sunglasses, and her blonde hair was worn braided in a high ponytail

Speaking to The Sydney Morning Herald in October, Madeline said they’d actually met two years before reports emerged of their relationship early last year. 

‘We have known each other for two years and met when I was modelling in Singapore,’ she said at the time.

It was also reported that Madeline was living in a penthouse apartment owned by Justin in the Sydney beachside suburb of Coogee.

Meeting the family: She added that while the majority of her family was yet to meet her beau, her older sister, Simone, 28 - who appeared as a finalist in the 2011 season of Australia's Next Top Model - was a fan

Meeting the family: She added that while the majority of her family was yet to meet her beau, her older sister, Simone, 28 – who appeared as a finalist in the 2011 season of Australia’s Next Top Model – was a fan

She added that while the majority of her family was yet to meet her beau, her older sister, Simone, 28 – who appeared as a finalist in the 2011 season of Australia’s Next Top Model – was a fan.

‘My parents and my sister Anna haven’t met him yet but Simone has been introduced to him and really liked him,’ she added. 

Both Justin and Madeline have kept their relationship largely private, with neither posting about the other on social media. 

Daddy's girls: Justin kept a watchful eye on his young daughters as they rode on the road beside him

Daddy’s girls: Justin kept a watchful eye on his young daughters as they rode on the road beside him

Read more at DailyMail.co.uk