It was during that investigation that a confrontation between Arenas and Crittenton was revealed, according to a Yahoo! Sports report.

The dispute stemmed from an unspecified disagreement, sources told Yahoo! Sports.

Citing an anonymous source, the New York Post reported in Friday's edition, however, that the standoff was sparked when Crittenton became angry at Arenas for refusing to make good on a gambling debt.

That prompted Arenas to draw on Crittenton, who then also grabbed for a gun, league security sources told the New York Post.

Asked by the newspaper about the confrontation, Arenas denied pulling a gun on Crittenton.

The Wizards on Friday afternoon released a statement regarding the alleged confrontation: "The Washington Wizards take this situation and the ongoing investigation very seriously. We are continuing to cooperate fully with the proper authorities and the NBA and will have no further comment at this time."

Arenas responded with a flurry of messages on Twitter, at times making light of the news but also making one tweet that read somewhat like a denial: "I understand this is serious..but if u ever met me you know i dont do serious things im a goof ball this story today dont sound goofy to me."

Arenas later tweeted he couldn't talk about the report the way he wanted to. He did not respond to a text message left by The Associated Press. A message left for Crittenton's agent also was not returned.

Arenas may not play Saturday against the San Antonio Spurs because of soreness in his left knee, Wizards head coach Flip Saunders told The Washington Post on Friday. Saunders would not comment on the reported dispute between Arenas and Crittenton.

At practice Friday afternoon, Arenas declined to answer questions about the allegations the New York Post and Yahoo! Sports reported. However, he did address the reports of the allegations, telling local TV station WJLA: "I like the story, it's intriguing."

Then, in response to questions whether anything had taken place between him and Crittenton, Arenas said: "I don't know."

"This is unprecedented in the history of sports," Billy Hunter, executive director of the NBA players' association, told the New York Post. "I've never heard of players pulling guns on each other in a locker room."

On Dec. 24, the Wizards issued a statement addressing Arenas' storage of unloaded firearms in a container in his locker at the arena and said that the NBA was looking into the situation. Arenas said he took his guns to the Verizon Center because he didn't want them in his house after the birth of his latest child. He said he later handed them over to team security to give to police.

"They just want to know where I got them from," Arenas said Tuesday night after a loss to the Oklahoma City Thunder. "They want to make sure they're not dirty guns."

On Tuesday, Washington police said they were investigating a report that weapons were found inside a locker room at the Verizon Center.

Now, the federal government is also involved. Ben Friedman, a spokesman for the U.S. Attorney's Office in Washington, told the New York Post "we're working with the Metropolitan Police Department on the investigation."

D.C. police said Friday they are assisting the U.S. Attorney's Office in the matter. The Wizards said they are cooperating and they "take this situation and the ongoing investigation very seriously." The team had no further comment.

The nation's capital has some of the most strict gun laws in the nation. The NBA's collective bargaining agreement allows for players to legally possess firearms, but prohibits them at league facilities or when traveling on league business.

Pending the outcome of the investigation, Arenas and Crittenton both could face fines or suspensions from the NBA. Commissioner David Stern has taken a strong stance on guns, saying in 2006: "We think this is an alarming subject, that although you'll read players saying how they feel safer with guns, in fact those guns actually make them less safe. And it's a real issue."

Arenas' father, Gilbert Arenas Sr., denied to The Washington Post on Friday that his son pulled a gun on his teammate.

"From the respect of guns being pulled in the locker room and at each other, yes, that's ludicrous," Arenas Sr. told The Washington Post. "Him bringing [them to] the locker room to keep away from his kids, that's true. Gil did not pull a gun on anybody. That's about all that I can say."

Arenas was suspended for Washington's season opener in 2004 because he failed to maintain proper registration of a handgun while living in California in 2003. Arenas, in the second season of a six-year, $111 million contract, formerly played for the Golden State Warriors.

Arenas didn't make the reports sound serious with his first tweet on the matter Friday: "i wake up this morning and seen i was the new JOHN WAYNE. ... Media is too funny."

Arenas, once known for his must-read blog, had vowed not to even use Twitter until he had one million followers. He broke his silence on New Year's Eve because he said it was taking too long to reach the goal. He had about 11,000 followers as of early Friday evening.

On Friday, he tweeted often, referencing the gun investigation while mixing in references to other topics.

"if ur not laughing i dont think u should follow me becuz im never serious and i will never not say anything dumb and silly," he wrote, before finally taking a break.

Arenas is averaging 22.7 points this season as he returns from knee surgeries that limited to 15 games over the previous two seasons. Crittenton has an injured left foot and hasn't played this season.

The reports are more bad news in a troublesome season for the Wizards, who are 10-20 and in last place in the Southeast Division.

Information from The Associated Press was used in this report.