In an effort to determine what Brett Favre did or did not text Jenn Sterger, the NFL is conducting high-tech forensic work to trace the electronic pathways and transmission of any photos or messages that might have been sent during communication between them, according to a source familiar with the situation.

It is the latest intriguing turn in a drama that features an iconic NFL quarterback and a former Jets subcontractor that has appeared on television.

To determine what Brett Favre did or did not text Jenn Sterger, the NFL is attempting to trace photos or messages that might have been sent, an ESPN source said. Bennett Raglin/Getty Images

Sterger met with the NFL earlier this month for three hours and provided league investigators with "substantial materials," according to her agent. Among the items turned over were cell-phone records, at least one phone and a SIM data card.

Favre is playing his former team Sunday as the Vikings host the Packers.

Favre remained upset Sunday morning with coach Brad Childress' postgame criticism of his performance in the teams' first meeting this season.

"It's a damn shame," Favre told ESPN's Ed Werder. "What I think about is going to my press conference knowing he had taken some shots at me.''

Favre has admitted to the NFL that he left voicemail messages to Sterger but not the racy photos that he also has been accused of sending.

The NFL's investigation, which is ongoing, is trying to determine whether the Vikings quarterback's denial is valid or whether more questions and issues need to be raised.

A decision does not appear imminent and is not likely to be made until after the forensic work is completed.

Meanwhile, Favre told ESPN's Werder that what he remembers most about the season's first Vikings-Packers game was neither the hostility from the fans at Lambeau Field nor the two fractures he suffered in his left foot.

Instead, it was Childress' angry postgame tirade in which he, among other things, admitted that he considered benching Favre and pointed out that he threw to the wrong receiver on one of his three interceptions.

Adam Schefter is ESPN's NFL Insider. Information from ESPN.com's Kevin Seifert was used in this report.