Houston ? A Houston man held on sex trafficking charges has now been accused of trying to intimidate witnesses and law officers.

A federal grand jury in Houston on Thursday returned a nine-count indictment against 42-year-old Andre McDaniels.

Investigators say McDaniels in January allegedly attempted to contact and threaten individuals who could testify against him.

McDaniels is one of six people indicted last year and accused of conspiracy, sex trafficking of children and forcing and coercing adults to engage in commercial sex acts. The investigation involves modeling studios and massage parlors in Houston, with ties to Kansas, Nevada, Arizona and Florida.

A witness tampering conviction carries a possible life term in prison.