The FBI has subpoenaed text messages from former Subway spokesman Jared Fogle in which he allegedly admits having paid $100 for sex with a 16-year-old girl.

Business Insider reports Fogle had been messaging a woman—who formerly worked as a Subway franchisee—with whom he was having a sexual relationship. In the messages, sent in 2008, Fogle allegedly asked the woman to advertise herself on Craigslist where she would offer sex with other men while Fogle watched.

This exchange led the woman to ask Fogle, "Is this the same website you found that 16-year-old girl that you f**ked…I still can't believe you only paid $100 for her." Fogle is said to have responded, "It was amazing," according to the report.

"This allegation, if true, is appalling and is contrary to the values of our brand," said a Subway brand spokeswoman. "As previously stated, we have suspended our relationship with Jared."

Business Insider spoke with the former franchisee's lawyer; both the lawyer and the franchisee asked to remain anonymous. The woman's relationship with Fogle allegedly took place between January and June 2008.

Although the age of consent is 16 in Indiana, where Fogle lives, the FBI has subpoenaed the messages as part of an ongoing investigation, the woman's lawyer tells Business Insider. It was unclear if the messages were being sought by authorities because they could be evidence of prostitution or because of Fogle's other alleged sexual references to minors. FBI officials would neither confirm nor deny that they were requesting the messages.

The woman brought the text messages to Subway after she became uncomfortable with her relationship with Fogle, but the brand did nothing with the information, Business Insider reports.

"We have no record that this alleged complaint was ever brought to our attention," said the Subway spokeswoman. "Had it been, we would have immediately taken action."

The woman is said to have met Fogle at a Subway function and then began a six-month relationship with him. When she began feeling uncomfortable in the relationship—he also allegedly asked to meet with her under-age cousin—the woman hired a lawyer to see if she had violated her franchisee contract.

The woman requested that all marketing materials or mentions of Fogle be removed from her store location. She is also said to have told Subway upper management that Fogle should "not be interacting with young people."

The text messages were taken from her phone in an affidavit, and that affidavit is what the FBI has subpoenaed, the woman's lawyer told Business Insider.

As Subway's pitchman for the past 15 years, Fogle helped boost the company's profile. Since suspending its relationship with Fogle, Subway has removed all mention of him from its website and social media accounts.

Subway's chief marketing officer Tony Pace is also on his way out. He will step down next month to start his own marketing consulting firm. Subway, which spent $534 million in media in 2014, is reviewing its creative business, which MMB handled for the last 10 years.