U.S. gold-medal-winning gymnast Gabby Douglas has slammed her father as a deadbeat dad, claiming he left her mother with mountains of bills.

The 16-year-old said that her father, Staff Sergeant Timothy Douglas, who served for the Air National Guard in Afghanistan, abandoned her and her three older siblings years ago and rarely paid child support.

It left her mother, Natalie Hawkins, struggling to provide for Gabby, her two older sisters and brother – and often got the gymnast so down that she considered quitting her Olympics dream.

And in a sign of Gabby’s resentment towards her father, Mr Douglas is in London for the Olympics but has not watched his daughter compete as she did not get him – or her grandparents – tickets, a source told MailOnline.

‘It was really hard for us growing up – my dad had left us, so he wasn’t really in the picture anymore,’ she told the New York Post.

‘So my mom had to front all these bills. My dad didn’t really pay the child support. He was short [on money]. It was definitely hard on her part and she had to take care of me and the rest of my siblings.’

Even after winning two gold medals – the individual and team titles – she revealed she had not been in touch with him, though he resided in a home just 10 miles away from her mother’s Virginia Beach property.

And when he appeared at the U.S. Olympic trials in June, brandishing an American flag with words of support, she had not seen him for two years.

Staff Sgt. Douglas, who is in the process of being divorced by her mother, was first deployed when Gabby was just nine years old, leaving Ms Hawkins to raise her four children on her own.

He is a structural craftsman and a traditional Guardsman, meaning he serves one weekend a month and two weeks every year unless mobilised for duty.

He was deployed to Southwest Asia in 2003, 2006 and 2011, with each lasting about eight months. He is currently enrolled in college with an undecided major.

The MailOnline can reveal that the couple initially separated in on July 2, 2007, according to the divorce filings that Ms Hawkins submitted in October 2009.

The two were married on April 23, 2005, in Chesapeake, Virginia, according to the filing, and identify Joyelle, Johnathan and Gabby as their three children. Arielle is not mentioned in the documents.

In the divorce filings, the couple resolved an agreement for the children’s college room, board and tuition, but Mr Douglas demanded joint custody and refused to offer Ms Hawkins any spousal support.

Ms Hawkins battled to raise the money to support her daughter’s dreams and, in interviews, she identifies as a single mother. Earlier this year, with debts nearing $80,000, she filed for bankruptcy.

Her father’s absence has haunted the teenager, who struggled to perform to the best of her abilities without her father by her side, and would often wake up with anxiety that he was at war in Iraq.

While living with her coach in Iowa, she would wake up and rush to her computer and try to contact him on Skype.

‘[I] just had bad days in the gym, thinking about my dad,’ she said to NBC before the Olympics. ’I’m just like “Whoa, what if he doesn’t come back [from Iraq]?” I was just horrified. I prayed every night.’

Earlier this year, she twisted her ankle at the Pacific Rim Championships in March. Her father’s absence and her injury caused her to contemplate quitting.

‘It was pretty drastic. She really, really sounded very serious about it,’ said Gabby’s sister, Arielle Hawkins.

She forged ahead anyway, competing with a heavy weight on her heart.

‘I’m like, “Who’s calling my name?” And then I look up, it was my dad and his friend, and I haven’t seen him in awhile,’ Gabby said to the Des Moines Register.

‘They were holding up the flag. And I almost fell like bawling. I was like, “Oh, my gosh, Dad!”‘

Serving in the 203rd Red Horse civil engineering squadron in Afghanistan, Mr Douglas would watch YouTube videos of his daughter’s routines on the dial-up internet available in Kandahar.

Watching his daughter perform so perfectly for the first time in real life was almost too much for the military man.

‘There’s an exuberance. There’s a feeling that you can’t describe,’ Mr Douglas said. ‘I just missed her so much.’

‘Sometimes, when she had a rough time, I’d tell her to hang in there. “You know what it takes to be a winner, you know what your goals are. You just keep on your goals”.’

In June, seeing her father put the skip back in her step. 

‘Before my floor and bar routine, I was like, “OK, you’ve got to get it together,”‘ Gabby said.

Watching her perform, he held up an American flag with the words: ‘I love America. God bless our Troops. Go Team USA. Go Gabby Douglasd. Love, Dad.’

‘Seeing him made my night, actually,‘ Gabby said.

He told the Des Moines Register that he would try to make it to London to watch his girl try for the gold, but it appears he wasn’t able to.

Mr Douglas said that it was obvious from the outset that he had a special little girl. When she was just seven-years old, she refused to stay home from the gym when she was sick.

‘We knew [gymnastics] was in her heart because one day she came home from the gym and she had a 102-degree temperature,’ Mr Douglas recalled.

‘She went to bed, slept it off and woke up and got back in the gym the next day. That’s when we knew she had a winner’s attitude, a winner’s spirit.’

He continued: ‘We knew she had that type of zeal, we knew she had that type of strength. We have a special young lady there, and I’m so proud of her.’

The family struggled to pay for her training, with Ms Hawkins alone in their Virginia Beach home.

‘Gymnastics is an expensive sport,’ Ms Hawkins said. The family applied for military scholarships to help fund Gabby’s training.

In 2006, she received a $500 grant from Our Military Kids, a non-profit that helps fund children’s activities while their parents are overseas. That funding paid for her to attend a gymnastics camp in Texas with renowned coaches Bela and Marta Karolyi – who helped her win the gold in London.

‘In the grand scheme of things, $500 may not seem like that much money, but it made the difference between keeping Gabby at home and sending her to a camp that would play a part in molding her into the Olympic gymnast she is today,’ Ms Hawkins said.

In fact, Ms Hawkins filed for bankruptcy earlier this year, according to documents seen by TMZ. The documents show she has debt totalling $79,754.14.

After the camp, Gabby told her mom, Natalie Hawkins, that she wanted to move from their home in Virginia Beach, Virginia, to train with Chow, who coached Shawn Johnson in 2008.

Ms Hawkins said absolutely not; there was no way she was allowing the youngest of her four children to move halfway across the country at 14.

But Gabby’s two older sisters lobbied on her behalf, giving their mother a list of reasons why Gabby should be allowed to go. The only reason to stay: They would miss her.

Ms Hawkins finally relented, but not without many second thoughts, including: ‘That I was crazy. I must have lost my marbles. But she wanted this more than anything.’

Reflecting on the journey that brought her the gold, Gabby seemed wiser than her years.

‘I just want people to know it took a lot,’ she said to Today.

‘It took a lot of hard days in the gym and determination, passion and drive. Gold medals are made out of your sweat, blood and tears, and effort in the gym every day, and sacrificing a lot.’

It was strain that showed yesterday when she stumbled during the uneven bars and finished in last place, but she has another chance for gold today when she takes part in the beam competition.

‘Toward the end of the Olympics, you get physically tired and drained. And no matter how much rest you have, your body is tired,’ she said. ‘I made a little mistake, but I’m human.

‘I’m going to go into the beam finals and try really hard to end on a good note.’

Elite.