Las Vegas police investigating a rape allegation against Cristiano Ronaldo have sent a warrant to Italian authorities for a sample of the Portuguese football superstar's DNA, a police spokeswoman said.

"The LVMPD (Las Vegas Metropolitan Police Department) is taking the same steps in this case as in any other sexual assault to facilitate the collection of DNA evidence," CNN quoted spokeswoman Laura Meltzer as saying on Thursday. 

"We can confirm that an official request has been submitted to Italian authorities."

The Wall Street Journal reported that the police sent the warrant to a court in Italy, where Ronaldo plays for famed club Juventus.

The Journal reported investigators want to see whether Ronaldo's DNA matches found on Kathryn Mayorga's dress.

Mayorga's has said in her lawsuit that Ronaldo, 33, raped her in a Las Vegas hotel room in 2009.

The lawsuit Ronaldo and his camp of taking advantage of her fragile emotional state to coerce her into signing a settlement and nondisclosure agreement. 

She claims she received $375,000 in exchange for her silence. Her lawsuit seeks to void the settlement and agreement. 

After Mayorga filed suit, the police reopened a criminal investigation into the case, which includes results of a medical exam.

"Ronaldo has always maintained, as he does today, that what occurred in Las Vegas in 2009 was consensual in nature, so it is not surprising that DNA would be present, nor that the police would make this very standard request as part of their investigation," the football star's attorney Peter S. Christiansen said in response on Thursday.

In October, Ronaldo had denied the allegation.