The illegal immigrant who allegedly murdered Iowa woman Mollie Tibbetts has asked US taxpayers to help fund the legal battle that could lead to his freedom, a report said on Wednesday.

Cristhian Bahena Rivera — who was working and living in the US illegally — asked the government for an initial $5,000 to pay a private investigation firm to work on his case, according to documents revealed by RadarOnline.

He has been charged with first-degree murder.

In the documents, Rivera notes the $5,000 amount is “probably considerably less than what will actually be necessary to conduct all investigation in this matter.”

A rep for the firm, Gratias Investigations, did not immediately return a request for comment by The Post.

Rivera, 24, allegedly murdered the 20-year-old Tibbetts near her home in Brooklyn, Iowa, on July 18.

The man had been working on a nearby farm under a fake name.