Billionaire couple David Siegel and his wife Jackie – known as the 'Queen of Versailles' – entertained a slew of celebrities at a lavish charity gala in their Vegas hotel last week.

Artists Barry Manilow, Dionne Warwick, Scott Stapp and Lee Greenwood joined reality stars Michael Lohan, Gretchen Rossi, Teresa Guidice and Phaedra Parks as well as actors Daniel Baldwin and Rebecca Holden on Friday at the 900-seat fundraiser to fight the opioid epidemic.

The star-studded Westgate Hotel gala raised $1.3million for the Victoria Siegel Foundation, named after the billionaire couple's 18-year-old daughter who died of a drug overdose in 2015.

No expense was spared by her father who footed the entire bill for the event, flying in celebrities on his GulfStream private jet and opening up his own 12,600 sq ft suite, formerly used by Elvis Presley as his Vegas residence, for a raucous afterparty.

Billionaire couple Jackie and David Siegel hosted a lavish gala at the Westgate Las Vegas hotel benefiting the Victoria Siegel Foundation, named after their 18-year-old daughter who died of a drug overdose in 2015

Private jet: The wealthy family flew out stars including Orange County Housewife Gretchen Rossi (left) and Atlanta Housewife Phaedra Parks (right) on David's GulfStream G550 worth $61.5million

Actor Daniel Baldwin and celebrity hypnotherapist Kimberly Friedmutter made an appearance at the gala, which raised a staggering $1.3million

David Siegel made his fortune in real estate, but the couple gained notoriety as the stars of award-winning 2012 documentary, The Queen of Versailles, which followed their struggles building a 90,000 sq ft estate in Florida inspired by the French palace of Versailles amid the 2008 financial crash.

Since the tragic death of their daughter from an accidental overdose of methadone and sertraline, the Siegels have been driven in their campaign to stop young Americans getting hooked on prescription narcotics.

In an interview with DailyMailTV, at the Victoria's Voice gala, David said the money raised from the event will help expand a scheme called Victory Clubs that signs up middle- and high-schoolers for random drug testing in exchange for perks such as free movie tickets, pizza and preferential parking.

'We're going to get the kids high on benefits instead of high on drugs,' said the billionaire philanthropist.

'All they have to do for all these benefits is to stay off drugs. They'll get drug tested to get into the club, and then they'll get randomly drug tested periodically.

'It has proven to reduce the overdose deaths in the communities where it already is, dramatically. We're taking an existing program that has been in effect for 14 years in the Ohio area and we're going to take it nationwide.'

The Siegels were instrumental in lobbying to get a law passed in 2016 to equip first responders across the country with overdose antidote Narcan, which David says has revived around 200,000 people from overdoses each year.

Entertainment: Veteran recording artist Barry Manilow performed at the event

Michael Lohan, who has overcome substance abuse, was invited to the event and told DailyMailTV he is working on charity song featuring stars Billy Ray Cyrus, Gladys Knight and others. Lohan, the father of Lindsay Lohan, now works with rehab centers to improve recovery rates

Real Housewives of Orange County star Gretchen Rossi, 41, with Phaedra Parks who starred in Real Housewives of Atlanta (left) and Artist Lee Greenwood (right)

Jackie said she believed her daughter wanted to help other teens avoid the downward spiral into drug abuse that she suffered.

In texts that Jackie found after her daughter's death, the girl told her to publish her private journal that detailed her addiction.

'I went up to her room by myself and I was shaking as I was pulling out the nightstand drawer. There it was. It was about four years old, very used,' Jackie told DailyMailTV.

'She had pictures taped in there. She had a little baggie of cocaine in there, from the first time she did cocaine like she was so proud.

Creed frontman Scott Stapp, 46, is close to the cause telling DailyMailTV his drug addiction almost led him to lose his family before he stopped using in 2004

'I was by myself and it was very hard for me. Only after reading the diary do I feel I now know my daughter. I know her much better dead than when she was alive.'

From their daughter's journal the bereaved parents discovered Victoria had moved on to heroin and a variety of prescription narcotics after beginning her opioid addiction with a doctor's prescription of Xanax.

'It turns out she'd found a drug dealer at school and he had a pill press,' said Jackie.

'He was making xanny bars. It's like four pills in one. She was getting them from school. She got super addicted. She could take like half a bottle.'

'She met a 26-year-old man, she was only 18,' David added. 'He turned her on to heroin and other drugs. That was the beginning of the end.'

The 2012 documentary The Queen of Versailles cast the Siegels as a notorious symbol of opulence while the US still struggled to recover from the 2008 financial crash, following the family as they worked on the construction of their 90,000 sq ft palace on the shore of Lake Butler, Florida.

The Siegels started building the 14-bedroom, 30-bathroom mega-mansion in 2004 and it is set to become America's largest home when it is finished - in a 'couple of years', according to David.

The billionaire couple put work temporarily on hold first after the crash nearly ruined them, and then after Victoria's death in 2015.

'After she overdosed we didn't even care about the house any more,' Jackie told DailyMailTV.

Jackie Siegel, who starred in the 2012 documentary Queen of Versailles, says she and her husband David now drug test their seven kids after their daughter Victoria died of an opioid overdose in June 2015

Victoria overdosed on methadone and antidepressants on June 6, 2015 while home alone as her family attended a Utah wedding. She was fresh out of rehab at the time. Victoria pictured left with mom Jackie and right with a friend

'We're sorry we ever started. But we're $50million in to it, so it really needs to get done.'

'We're not as motivated to finish it or live in it as we were when we first started construction,' David added.

'The important thing in my life is to save lives. I don't care about houses, I don't care about business, I don't care about money. I want to save lives.'

Among the host of celebrities who came to the Siegels' gala on Friday night were several whose lives had been impacted by drug addiction.

Creed lead singer Scott Stapp told DailyMailTV how his drug addiction, which began with pain medication he was prescribed after a car crash, led him to almost lose his wife and kids before he stopped using in 2004.

'I found myself doctor-shopping, lying about injuries. Whatever I could do, because the withdrawals are so intense you'll do anything,' the singer said.

'My wife basically put her foot down and said, "this has gotta stop or we're gone." Loved ones at times need to show someone who's wrapped up in the compulsion of addiction very tough love.

'My wife knew that cutting me off from her and my children, that was the last straw. She was hoping that would get through to me, and it did.'

The Creed frontman said he was 'honored' to be a part of the Siegel's gala.

'What David's already done in helping get the legislation passed to get Narcan to all the first responders, it would have saved his daughter's life, and now it's saving thousands and thousands of lives.'

Lindsay Lohan's father, Michael Lohan, who now works with rehab centers to improve recovery rates, told DailyMailTV he is working on a new charity song by a supergroup including Miley Cyrus' father Billy Ray Cyrus, soul legend Gladys Knight, R&B star Mýa Harrison, and former rock group Kansas frontman John Elephante, to raise money for drug abuse causes.

The unfinished Versailles mansion in Windemere, Florida pictured above. The opulent future 90,000-square-foot mansion started construction in 2004 and will feature a roller rink and discotheque, nine kitchens, 30 bathrooms and 14 bedrooms

The Siegels told DailyMailTV, after their daughter's death they don't care about the project anymore and said they're 'sorry we ever started'

The song, Lohan said, is inspired by Dionne Warwick's charity single, 'We Are the World' and is written and produced by her son, Damon Elliot.

Lohan explained how substance abuse still impacts his life, describing how his estranged wife's alcoholism led to their two young boys being taken into foster care for months in 2015.

Child Protective Services took the kids away from the reality star, who also has a history of domestic violence and drug abuse, after a video emerged of an explosive fight with his wife Kate Major Lohan when she turned up at his house drunk, he claims.

'Kate was at the house when she wasn't supposed to be there,' he told DailyMailTV.

'Just because she was there wasn't grounds to take my kids away. It didn't last a long time, but just that short amount of time had an impact on my children.

'The foster care system in Florida is severely broken. They didn't check the people that they were with, and there were three reports of abuse that had to be dealt with and they did nothing about it. Finally, I got the kids back.

'It wasn't long enough to really affect them with regard to my relationship with them. You never know what the effects of that trauma are until later on in life, and that's something I keep a close eye on.

'The kids did go to therapy, and they're just normal little boys.'

Other reality stars joined Lohan at the Victoria's Voice gala after flying in to Vegas on the Siegel's private jet, a 12-seat GulfStream G550 worth $61.5million.

Real Housewives of Orange County star Gretchen Rossi, 41, and baby daddy Slade Smiley, 46, took their three-month old baby, Skylar Gray Smiley, on the jet for her first ever flight.

The couple, who went through multiple rounds of in vitro fertilization and a vasectomy reversal, posed on the steps of the jet at a Los Angeles private airport and told DailyMailTV their delight at being able to treat their daughter to her first air travel in style, in an exclusive video.

Joining them on the plane was Real Housewives of Atlanta star Phaedra Parks, who is rumored to me moving to LA to be closer to her new boyfriend, 'Haves and Have Nots' actor Medina Islam, who she will be joining on the 2020 season of Marriage Boot Camp.