DENVER -- An Arapahoe County man under investigation for ties to terrorist groups was arrested Saturday night, as was his father.

Najibullah Zazi and his father, Mohammad Zazi, were taken into custody at their home at about 9:40 p.m.

Federal authorities have filed criminal charges Zazi, his father, and a third man in the New York area, sources told ABC News. The name of the third man has not been released but it is believed to be one of the men Zazi was staying with when he visited New York last week.

Although it is not known yet on what grounds Zazi was taken into custody, the likely charge against Zazi will be making false statements to FBI agents, ABC News said. Federal authorities are attacking Zazi on alleged inconsistencies in what he's told the FBI about his travels and associations.

Sources say the criminal complains will take the men off the street while the FBI attempts to build a case that Zazi and others have provided support to al-Qaida.

The government does not yet have enough to file terrorism charges, ABC News reported.

Report: Text Shows Plot Was Near Attack Phase

ABCNews also reported Saturday that Zazi had researched baseball and football stadiums and sites used in the recent Fashion Week event in New York City, quoting officials familiar with the case.

The officials said they do not know the targets of the alleged plot, but the contents of Zazi's computer are considered a valuable insight into what he might have been planning.

They also said text messages sent by Zazi suggested the plot was nearing the attack phase. One message said the "wedding cake is ready," which authorities said may have been code saying the attack was ready.

A senior U.S. intelligence official said Zazi played a crucial role in an intended terrorist attack.

Zazi's attorney, Arthur Folsom, said the 24-year-old airport shuttle driver has never met with al-Qaida operatives and isn't involved in terrorism. In an exclusive interview Friday night, Folsom denied reports of any plea deal related to terror charges.

"There has been no plea deal offered," Folsom said. "There have been no plea discussions going on. I don't know what it is that is coming out on that."

4th Day Of FBI Questioning Refused

Zazi completed a third day of questioning by FBI agents in Denver Friday but was allowed to return to his apartment.

Zazi was supposed to go to the federal building in Denver on Saturday morning, but Wendy Aiello, a spokeswoman for Zazi's defense team, said that Zazi wouldn't be meeting with the FBI. Aiello released a statement saying "Mr. Zazi and his attorney, Arthur Folsom, will not be meeting with the FBI today. Mr. Zazi and Mr. Folsom have met with the FBI voluntarily at length over the last three days. Mr. Folsom will be consulting with his client today; no additional meetings with the FBI are scheduled."

The FBI had no immediate comment.

The Denver Post reported on Saturday that Zazi said in a telephone interview that he had not admitted any link to al-Qaida, to participation in insurgency training in Pakistan or to involvement in a terrorist plot.

"If it was true, they wouldn't allow me to leave," Zazi told the paper. "I don't think the FBI or the police would allow anyone who admits being a terrorist to go free for one minute."

A senior U.S. intelligence official told ABC News on Friday that Zazi has indicated he is directly linked with al-Qaida. The official, who spoke on condition of anonymity in order to discuss intelligence matters, said Zazi played a crucial role in an intended terrorist attack, and the plot was being directed from outside the United States.

"Absolutely no way. It's a rumor," Folsom said Friday.

The FBI has searched Zazi's apartment and his uncle and aunt's home in Aurora. Authorities have not said what they found and have made no public statements on the investigation.

Another official familiar with the investigation told the AP on Thursday that agents have been monitoring Zazi and four others in Colorado as part of a terrorism investigation.

U.S. Attorney General Eric Holder said Friday that the FBI was "working this case around the clock" in New York, Denver and other parts of the country but that there was no imminent threat.

Authorities say Zazi rented a car and drove from Denver to New York, crossing into Manhattan on Sept. 10. Zazi said he went to New York to resolve some issues with a coffee cart he owns in Manhattan.

On Monday, FBI agents and police officers with search warrants seeking bomb materials searched three apartments and questioned residents in the Queens neighborhood where Zazi stayed.

A joint FBI-New York Police Department task force feared Zazi may have been involved in a potential plot involving hydrogen peroxide-based explosives like those cited in an intelligence warning issued Monday, according to two other law enforcement officials, who spoke on condition of anonymity because they were not authorized to speak about the investigation.

Folsom has repeatedly denied any such claims.

Zazi was born in Afghanistan in 1985, moved to Pakistan at age 7 and emigrated to the United States in 1999. He returned to Pakistan in 2007 and 2008 to visit his wife, Folsom said.