CNBC tried to contact the firm, but the number listed on the SEC filing proposing the acquisition is a mobile phone that goes straight to voicemail.
Avon later confirmed it had not received an offer from PTG and has not confirmed the firm's existence.
PTG Capital Partners named a Texas-based attorney, Michael Trose, in their filing. The Texas State Bar, however, has no record of any attorney named Trose.
The address and phone number for Trose in the filing belonged to Atrium Executive Business Centers in Fort Worth, Texas. "I've never heard of him, and I've been here for 10 years," said Sue Vis, a manager at Atrium.
The filing also listed PTG's address as 125 Broad ST., a well-known business office in London. The building's reception, however, told CNBC there is no such business located there.
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Meanwhile, a source familiar with the situation at TPG Capital told CNBC it did not make the filing.
The Avon Lady has seen better days. On April 30, the company reported first-quarter earnings and revenue below analysts' expectations. It also said that year-over-year revenues fell by 18 percent, citing strong currency headwinds.
CEO Sheri McCoy has endeavored to turn the company around and improve its struggling U.S. business.
"Despite continued foreign exchange pressure, I'm really impressed with how well our teams in market are managing in this volatile environment. This is a payoff for the work we've done over the past two years on strengthening our talent and improving core processes," said McCoy, in a statement that day.
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The company also paid $135 million in December to settle criminal and civil charges after its China unit pleaded guilty to conspiring to violate the Foreign Corrupt Practices Act by bribing officials there.
The company's stock has also fallen nearly 80 percent in the last five years and remains well below its all-time closing high of $46.14, which was reached in 2004.
Avon shares traded around $7.05 in afternoon trading and reached a session high of $8. Click here to see where it is trading now.
—The Associated Press contributed to this report.