Kourtney Kardashian Faces Court Battle Over Mason Paternity Claim: Accuser Consults Top Lawyer, Demands DNA Test

The male model who believes he is the father of Kourtney Kardashian's son, Mason, has consulted a top Los Angeles attorney who once represented Larry Birkhead in his successful paternity case against late Playboy model Anna Nicole Smith.

And Michael Girgenti, who claims he and Kourtney had a fling in March 2009 when she was on a break from her partner Scott Disick, has a "fighting chance" to prove he's the three-year-old father, according to California family law attorney Debra Opri.

Opri met with Girgenti on May 14, In Touch magazine is reporting.

A member of Michael’s family tells the publication: “It was killing him not knowing the truth. It became obvious to Michael that she and Mason do not share the same father."

Kourtney, 34, is also speaking out about the claims for the first time, with a lawyer for the E! star calling the allegations "preposterous and an outrageous lie."

"She certainly has never intimately been with Mr. Girgenti," her attorney said.

As RadarOnline.com previously reported, Girgenti wrote Kourtney a letter demanding that she get a DNA test for the toddler — or he’ll sue.

“This is Kourtney’s last chance,” Michael said in an interview earlier this month.

“My next step will be to take her to court and sue her for a paternity test. I’m tired of not knowing if Mason is my child and I want the constant wondering to end.”