By Yereth Rosen

ANCHORAGE, Alaska, Jan 3 (Reuters) - An Anchorage man accused of injecting a 14-year-old girl with heroin was indicted for manslaughter on Tuesday, five days after she died from an overdose, an Anchorage police spokesman said.

Sean Warner, 26, was indicted on one count of manslaughter by a state grand jury, Anchorage Police Lieutenant Dave Parker said, adding that an additional charge could still be filed against Warner.

Warner was arrested last month on drug-related charges after 14-year-old Jena Dolstad, a high school student, was found overdosed and lying on Warner's bed in her own vomit, according to a charging document.

She died in a local hospital, where she never regained consciousness and was kept on life support for days, Anchorage police said.

Dolstad had been at a gathering at Warner's house the previous night and had asked to try heroin, but was unwilling to inject herself, the charging document said. Warner then injected the drug, but warned her of the dangers of addiction, according to a witness account included in the court papers.

When Dolstad was found the next morning, Warner waited several hours before calling for assistance, the charging document said, adding that he also tried to hide heroin-related evidence.

Warner is a former Navy medic who served in Afghanistan, his aunt and uncle told local KTUU-TV, saying that Warner had returned from Afghanistan using heroin and suffering from post-traumatic stress.

Warner had been held in the Anchorage jail since Dec. 25 on the original charges filed against him, including drug delivery, contributing to delinquency of a minor, evidence tampering and theft. (Editing by Dan Whitcomb and Cynthia Johnston)