The death of Simone Battle has been ruled a suicide by hanging, authorities said Sunday, Sept. 7, the Associated Press reported.

The cause her death was determined two days after the 25-year-old G.R.L. singer was found dead in her West Hollywood home, Los Angeles County Coroner's Lt. Fred Corral said.

Simone's father, Anthony, told TMZ that his daughter had not spoken to him on the phone in a few weeks but he said that they had texted every day and she seemed to be doing just fine.

In fact, Anthony said that his daughter was excited about the progress of her career. G.R.L., which is originally a reboot of the Pussycat Dolls, was featured on rapper Pitbull's hit song "Wild Wild Love" earlier this year, and this collaboration served as the group's stepping stone to launch their debut single, "Ugly Heart" in June.

Sources also told the celebrity gossip website that close friends of the "X Factor" alum spoke with her through text the night before she committed suicide, and they, too, did not feel anything was wrong.

When asked if his daughter was battling depression, Anthony said he was unaware of anything like that. He, however, acknowledged, "It's possible she may have had an invisible disability," according TMZ.

Anthony also told the website that Simone's boyfriend was the one who discovered Simone's body in her bedroom.

Tributes from celebrities especially from those who had worked with Simone's continue to roll in, according to news.com.au.

"I am so sad to hear about the news Simone Battle has passed away. She was such a fun nice person. It's such a loss. Rest in peace Simone," Simon Cowell tweeted.

"Devastated & upset to hear about the passing of @GRLSimone," Pussycat Doll member Nicole Scherzinger posted on the microblogging site. "My prayers go out to her family @robinantinpcd @GRL & my ReignDeer family."

"My heart & prayers go out 2 @GRLSimone's family, band mates, & loved ones. Such a beautiful sweet promising star. May she rest in peace," wrote Paula Abdul.

Meanwhile, Nova Entertainment cancelled G.R.L.'s planned gig at Marquee nightclub in Las Vegas on Monday, Sept. 8 following Simone's passing, Las Vegas NV Blog reported. This is to give Simone's band members Lauren Bennett, Natasha Slayton, Emmalyn Estrada and Paula von Oppen to grieve the loss of their friend.