Inside the tragic life of reclusive Versace heiress

After fashion designer Gianni Versace was gunned down by Andrew Cunanan in 1997, many of the world's most recognisable celebrities gathered to pay their respects.

Among them were the likes of Princess Diana, Elton John and Sting.

But among the glitz and a glam one girl stood out - a little girl who was mourning the loss of her uncle.

Her name was Allegra Beck, and little did she know the death of her uncle would change her life forever.

At age 11, she was set to one day become the most powerful woman in the fashion industry.

But 21 years on any sign of Allegra's wealth, status and existence have been well and truly hidden.

In the new FX TV series The Assassination of Gianni Versace: American Crime Story, Allegra was wiped from the show at the request of her mother Donatella, the New York Post reported.

"The Versace family has neither authorised nor had any involvement whatsoever in the forthcoming TV series about the death of Mr. Gianni Versace," a statement read.

Donatella didn't want her daughter portrayed on the show.

Aged 31, and worth a reported $US800 million, Allegra has remained intensely private. She is rarely seen in public and has in the past suffered from a debilitating eating disorder.

According to a former employee at the fashion brand's headquarters, Allegra works for the company but is not "running anything at Versace" and the 31-year-old "loses her mind" if she sees herself or photos of her on TV, they told the New York Post.

She also suffers from body dysmorphic disorder.

"She's utterly insecure, frail and never a contender for design," the former employee revealed.

"She just stays [at home] and binges on TV and music."

So why did Gianni choose Allegra to inherit his fame and fortune?

A young Allegra was "the best-dressed girl in Milan" and as she grew older became absorbed in the Versaces' love of style.

Her uncle was also attracted to Allegra's honestly, studious nature and ability to speak her mind.

But when Gianni was murdered, Allegra felt guilty and questioned her uncle's choice of handing her the future keys to the fashion company.

According to insiders, Gianni's death sent the young girl on a downward spiral.

"She was never the same, absolutely destroyed by it," one insider told the New York Post.

In the mid 2000s she started to get thinner before the family in 2007 releasing a statement that read: "Our daughter Allegra has been battling anorexia, a very serious disease, for many years. She is receiving the best medical care possible to help overcome this illness and is responding well."

Allegra's mother Donatella became addicted to cocaine in 1987, tarnishing the Versace brand despite Gianni claiming he never touching the drug.

Donatella quit the drug before taking it up again following the murder of her brother. Her world began to crumble.

She went to rehab in 2004, but according to an insider, Donatella's unstable addiction impacted her own daughter.

"Having a mother like Donatella would intimidate [anyone] — so you can imagine the effect on her own daughter. Plus, look at what her mother's done to her own face, and you know something about the insecurity and distortion that runs in that family."

A former employee also told the Post that Allegra's romantic life appears non-existent.

"I've never seen her with a man — or a woman. She's either alone or only with members of her family."

As for her future, one family source believes Allegra will never fully recover from the loss of her uncle.

"[She's] stunted in childhood, will never develop. She is unlikely to ever function as an adult. This is the effect that Gianni's murder had on her."