Ronan Keating leads tributes to Stephen Gately on what would have been his 40th birthday

Chloe Best

Ronan Keating took time to remember his late friend Stephen Gately on what would have been his 40th birthday on Thursday. The Boyzone star passed away in October 2009 from an undiagnosed heart condition, and Ronan said it was "not fair" that Stephen had died so young as he tried to imagine how they would have celebrated his milestone birthday.

Sharing a photo of Stephen when he was younger, Ronan wrote: "Hey Bro. Happy Birthday. Trying to imagine what we all would have done to celebrate your 40th. Maybe a spot of can can dancing at Moulin rouge or a trip to Disney land and you would have us all dress up as your favourite princess.

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Ronan Keating paid tribute to his late friend Stephen Gately

"It's not fair that you are not here but your Boyz are always wearing your colours. We all miss you buddy. I know you are celebrating up there straw balls. #ShootingStar."

His bandmate Keith Duffy also shared an old photo of Stephen on social media, writing: "Tomorrow marks the day of what would of been Steo's 40th birthday! There will be fire works in Heaven! Love you pal xx".

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Keith Duffy also shared an old photo with his late bandmate

The BoyzLife star later posted an image of himself and Stephen performing together, telling fans: "He will always be holding my heart! Happy Birthday Steo xxx".

Shane Lynch followed suit by posting a collage of images of himself and Stephen, telling him he would "give it a go" celebrating both the late singer's birthday and St. Patrick's Day.

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Shane Lynch posted a collage of photos of himself and Stephen

"Miss ya STEO..Happy birthday brother… And happy paddy's.. This would have been 1 crazy 40th… But I'm still gonna give it a go for ya.. One love #steo #stephengately."

Stephen was just 33 when he died at his home in Majorca from pulmonary edema – fluid on the lung – caused by an undiagnosed heart condition. His devastated bandmates came together to give him a traditional Irish send-off in Dublin and have continued to pay tribute to Stephen, who they affectionately call Steo, during their live tours over the past few years.