Robert Fabian, charged with killing girlfriend Zuzu Verk, allegedly said 'I know a really big secret'

A west Texas man has been indicted on a first-degree murder charge in the killing of his university student girlfriend.

The remains of Zuzu Verk were found last month in a shallow grave in the wilderness near Alpine, about 321 kilometres southeast of El Paso.

A Brewster County grand jury indicted 22-year-old Robert Fabian on Friday in the death of Verk, a student at Sul Ross State University in Alpine.

His bond is set at $US750,000 ($975,000).

He already was jailed on $US175,000 bond on an evidence tampering charge. His lawyer didn't immediately respond to messages seeking comment.

Verk, of Keller, went missing on October 12. Her remains were found on February 3 and identified through dental records.

Neighbours have said they heard Fabian and Verk argue at his Alpine apartment late evening on October 11.

Verk is set to be buried tomorrow by her family.

Fabian had told police he planned a romantic dinner with his girlfriend on October 11 but it ended abruptly after they allegedly fought about an ex girlfriend of his.

Police have also charged his friend Chris Estrada with helping him dispose of Verk's body.

Estrada has admitted he drove Fabian to a store on October 12 and let him use his card to buy plastic sheets, the type Verk's body was wrapped in when it was found.

Neighbours also told police that Fabian had played a movie loudly between 1am and 2am, and had then driven off alone at around 4am.

And one friend told police that he had said: "If I know a really big secret and two people know it, then the other has to be dead."