Denver attorney M. Colin Bresee confirmed to The Associated Press on Friday a statement he gave to The Denver Post, saying the woman asked Andersen for "financial remuneration" after traveling to Colorado last year.
Bresee's statement says he expects that a Douglas County sheriff's task force that investigates allegations of cybercrime against children will find no criminal wrongdoing by Andersen. Bresee also said he expects the investigation will take about three weeks.
Authorities confirm that the cybercrime unit began investigating Andersen in February after a law enforcement tip from California. Sheriff's officials, citing the ongoing investigation, declined to comment about Bresee's statement.
"A female fan in 2010 mailed Mr. Andersen multiple letters and included several photos in which she was scantily clad," Bresee's statement reads. "Chris and this woman communicated with each other and in 2011, this woman, who represented herself as 21 years of age, flew to Colorado, showing her required identification."
The statement continued: "After leaving Colorado, she became upset at his lack of interest. In 2012, she threatened to retaliate if he did not provide financial remuneration."
Someone claiming to be the woman's mother wrote in an email that "i (sic) want him to pay for everything on her Amazon wish list, 5K for her bedding stuff and her victoria secret wish list," according to the statement.
Bresee, who was not at his office, declined to further comment when reached by cellphone. Andersen's agent and attorney, Mark Bryant, did not return multiple messages.
Douglas County sheriff's spokesman Sgt. Ron Hanavan said property, including electronic devices, was seized at Andersen's Larkspur, Colo., home Thursday as part of the investigation.
Andersen has not been arrested or charged, and no arrest is imminent, Hanavan said.
"We're sifting through property recovered to figure what, if any crimes, have been committed," Hanavan said.
Items generally collected during such investigations include computers, hard drives and thumb drives. Hanavan said the items from Andersen's home have been sent to the multi-agency Rocky Mountain Regional Computer Forensics Laboratory in suburban Denver. The lab has a backlog of computers awaiting analysis by investigators who retrieve information, find out where additional information may be stored on other servers, as well as determine who used the computer.
An application for a search warrant, where authorities explain to a judge their reasons for searching a home, as well as the return warrant, which contains details of what items have been seized, have been sealed by a judge. Such a move is standard during ongoing investigations, according to court and sheriff's officials.
Sheriff's officials also don't usually provide information about searches or ongoing investigations, but did in this case because of a rush of inquiries.
Hanavan said the sheriff's office will also announce the results of their investigation, including whether investigators decide to recommend charges against Andersen.
The Nuggets on Thursday said Andersen was excused indefinitely from all team-related activities.
With his colorful tattoos and high-flying, shot-blocking act, Andersen has long been a fan favorite. Before Thursday game, fans could still buy blue and yellow Mohawk "Birdman" hats.
The 10th-year pro hasn't played in the postseason after averaging 5.3 points and 4.6 rebounds during the regular season.
Andersen began his career in Denver in 2001 and headed to New Orleans three seasons later. His career was derailed when NBA officials suspended him in 2006, saying he violated the league's drug policy. Following a ban that lasted more than two years, Andersen returned to New Orleans late in 2008.
Since his return, Andersen worked to support youth charities, according to the Nuggets' media guide.