Anna Nicole Smith's Former Partner Larry Birkhead Shares Candid Photo of Them on 15th Anniversary of Her Death

Tuesday marks the 15th anniversary of the former 'Playboy' model's tragic death.

Larry Birkhead is remembering his time with the late Anna Nicole Smith on the 15th anniversary of her tragic death. On Tuesday, Birkhead shared a photo of the two cuddling and paid tribute to the model.

Birkhead is the father of Smith's now 15-year-old daughter, Dannielynn. In his Instagram post, the 49-year-old photographer and Smith have big smiles as they wrap their arms around one another.

"Still remembering this one 15 years after her death," Birkhead wrote. "She was truly one of a kind. She struggled for love and acceptance. Just when she found a little piece of one or the other, life seemed to sabotage."

"Today, I remember your heart, your soul and your beauty, both inside and out," he continued. "Your love is alive still to this day, in the form of a truly one of a kind teenager with her Mom's smile, beauty and courage. Thanks to Anna's fans for helping keep her memory alive. We love you Anna Nicole #annanicolesmith #loveisalive #ifmomcouldseeyounow."

Smith was found dead in her hotel room in Florida on Feb. 8, 2007, and her death was ruled as an accidental drug overdose. She was 39 years old. Prior to her death, she suffered a tragedy when her son, Daniel Smith, died in September 2006 just three days after she gave birth to Dannielynn in the Bahamas. His death was also ruled as an accidental overdose. He was 20 years old.

Smith, a former Playboy Playmate of the Year, was a tabloid fixture after she married 89-year-old oil tycoon J. Howard Marshall II and got into a legal battle with Marshall's family over his estimated $500 million fortune after his death. Smith later made more headlines due to the paternity battle over Dannielynn. Birkhead and Smith's partner at the time, Howard K. Stern, as well as two other men claimed to be Dannielynn's father. A DNA test later confirmed Birkhead was her father.

ET spoke with Birkhead in September 2017, and he talked about raising Dannielynn as a single father. He said that his daughter didn't ask too many questions about Smith, though he had faced some awkward moments, like explaining why her Wikipedia page states that her surname was "Stern" as a baby (Stern was listed as the father on Dannielynn's birth certificate, before the DNA test proved Birkhead was her dad). He said she was "more accepting" of missing her mom as she got older, though craved a motherly figure.

"I think [Anna and Dannielynn are] similar in a lot of ways," Birkhead noted. "A lot of times, I make decisions and think about what Anna would think, or what she would think I did that for."

Birkhead also shared intimate thoughts from Smith's private diary with ET. Watch the video below for more.