COLLEGE STATION, Texas -- Investigators with the College Station Narcotics Unit have obtained 16 additional warrants for six Sigma Nu Fraternity members, who attended a party that ended in the death of a fraternity member.

The warrants are for six new individuals, not the four members that were placed into custody for drug possession, following the death of Anton Gridnev on August 20. The warrants range from possession of marijuana to manufacture and delivery of a controlled substance.

All six men were residents of the Sigma Nu Fraternity House at the time of the incident, according to police. Investigators are currently working to get the men into custody. Their names will not be released until they are arrested.

Witness told police Gridnev had been celebrating his birthday and had taken an unknown amount of drugs, including Alprazolam, Hydrocodone, ecstasy and possibly heroin. He is believed to have died of an overdose.

Results from an autopsy are still pending.

No one has been charged for Gridnev's death. The case is still under investigation.