Updated

The Austrian man accused of imprisoning his daughter for 24 years and fathering her seven children likely will face a murder charge that could bring a life sentence, the Daily Mail reported Friday.

DNA results showed Josef Fritzl was the father of his daughter Elisabeth Fritzl’s six children, but the 73-year-old reportedly neglected a seventh child, who died, and threw the body in the incinerator.

Josef Fritzl allegedly failed to get help for the newborn, a twin named Michael who was just 3 days old when he died in the dungeon 12 years ago, the Mail reported.

• Click here to see photos of Josef Fritzl and the "House of Horrors."

"It needs to be proved that the baby would have survived had he got proper medical attention,” said Gerhard Sedlacek, a spokesman for the prosecutor’s office, after a 15-minute hearing at which prosecutors detailed their plans for investigation of the case.

"That carries a life sentence — and life means life; if convicted, he will spend the rest of his days behind bars.”

The judge on Friday ruled that Fritzl — suspected of keeping his daughter captive in a dungeon for more than two decades — should remain in custody, an official said.

The decision extends Josef Fritzl's pretrial detention by a month, according to St. Poelten provincial court spokesman Franz Cutka. It was made during a routine, closed-door session required under Austrian law and will be re-evaluated in June.

Fritzl's lawyer declined to comment.

Fritzl, 73, was formally placed in confinement April 29. He had been detained three days earlier on suspicion of locking up his daughter Elisabeth for 24 years and fathering her seven children.

Authorities say Fritzl has confessed to locking up his daughter and repeatedly raping and impregnating her. Investigators say he also told them three of the children were raised in a cellar at his home in Amstetten, three others were brought up above ground and one died in infancy.

He is expected to be charged once the investigations are completed. In Amstetten, west of the capital Vienna, detectives continued to comb through the vast Fritzl property for evidence.

Fritzl's alleged double life began to fall apart when Elisabeth's oldest child, a 19-year-old woman, was hospitalized with a severe infection.

Unable to find medical records for the woman, doctors appealed to her mother to come forward. Fritzl accompanied Elisabeth to the hospital April 26 and was detained after she divulged what had allegedly happened to her.

In comments relayed through his lawyer and published in the Austrian magazine News on Thursday, Fritzl was quoted as saying he knew it was wrong to hold his daughter captive and that he "must have been crazy" for doing so. He added that he tried to care for her and their children as best as he could by taking them flowers, toys and books, according to the interview.

Click here for more on this story from the Daily Mail.

The Associated Press contributed to this report.