The Arapahoe County man under FBI investigation for alleged ties to a New York bomb plot has admitted he has ties to al-Qaida and is in negotiations to plead guilty to a terror charge, a senior law enforcement official told ABC News.The official said Najibullah Zazi had received explosives training in Pakistan and his possible guilty plea would be part of a deal to cooperate with the government.However, Zazi's attorney Arthur Folsom told ABC News that no plea deal has been reached."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."The 24-year-old Zazi had insisted he had "no ties, no connection to al-Qaida" in interviews with reporters earlier this week.But after two eight-hour interrogations at the FBI offices in Denver on Wednesday and Thursday, Zazi told a different story Friday morning, the law enforcement official said.Zazi left FBI offices on Friday evening and is expected back for another day of questioning with authorities on Saturday, Folsom said.Officials said Zazi, his lawyer, and federal prosecutors were in discussions that would involve the suspect pleading guilty to providing "material support" for terrorism, ABC News reported.He is not admitting he was going to carry out any terrorist plot but he was involved, ABC said. Authorities said if Zazi fully cooperates as a witness in return for a lighter sentence, his knowledge of possible targeting and other plots aimed at the United States could provide an intelligence windfall.Folsom, through a public relations firm, called the reports "completely unfounded."Zazi works as an airport shuttle driver with his father. His father, Mohammad Zazi, was asked to report to the federal building in downtown Denver at 1 p.m. for questioning. Mohammad Zazi left the federal building just before 4 p.m.He did not say what kind of questions the FBI asked him but said he is in the dark about his son's alleged involvement with al-Qaida."I didn't see him. And I didn't talk with his people. I don't know what's going on. And I want to find out what's going on and nobody tell me," Mohammad Zazi said.Zazi has been under investigation for almost a year, according to law enforcement and intelligence officials who spoke to ABC News. The CIA reportedly first learned of his al-Qaida ties when Zazi visited Pakistan and officials said they later learned of "deeply troubling" conversations that were picked up on government intercepts.Zazi's attorney told 7NEWS that Zazi is married to a young woman who lives in Pakistan and travels there about once a year in order to see her. However, 7NEWS has learned that in a bankruptcy filing from March, Zazi said he was single.Zazi lives in an apartment on Smoky Hill Road and E-470 with his father and several relatives. Zazi's entire family is cooperating with authorities, 7NEWS reported.Law enforcement officials told ABC News that they have questioned at least 12 young men in New York connected to Zazi, who arrived in New York after a 1,777 mile drive from Denver in a rental car taken out in his father's name. The FBI has taken them in individually for questioning and some have been released and others not released, law enforcement officials said.Other men are being questioned in other parts of the country besides Denver and New York, authorities said.After Zazi's trip to New York, heavily armed FBI agents and police raided three homes in Queens, New York.ABC News reported that authorities found 12 new black backpacks they suspect were going to be used to carry homemade bombs and a laptop computer. Authorities told ABC News that the computer contained bomb making directions and an explosives recipe that would have produced homemade bombs of the same size and type used in the terror attacks on the London subways in July 2005.Two days after the New York raids, FBI agents raided Zazi's home in and his aunt's Aurora home.Folsom said he does not know what was removed from Zazi's home but maintained that no explosives or bomb-making materials were found.No one has been arrested in the case and no explosives have been found -- either in Colorado or New York.Zazi and his attorney arrived at the FBI's Denver headquarters Friday at about 9 a.m. They were driven to the downtown building by FBI agents in large black Chevrolet Suburbans and entered a garage in the back of the building. Zazi spent 8 1/2 hours answering questions Wednesday, and 8 hours on Thursday answering questions.Folsom said the questioning has been detailed, and gone in chronological order from his trip to Pakistan, to his drive to New York to his stay in New York.Folsom earlier said Zazi is cooperating fully and answering all FBI questions because he wants to clear his name.There's no word on yet on whether Zazi will be arrested or if he will be allowed to go home.