Authorities search for former Slack CEO's teenager who is considered a runaway

Authorities in California are searching for the teenage child of former Slack CEO Stewart Butterfield.

Mint Butterfield, the ex-tech co-founder's child, is considered a runaway, the Marin County Sheriff’s Office said in a statement Tuesday. Mint was last seen Sunday in Bolinas and reported missing Monday morning, it said.

Bolinas is about 30 miles northwest of San Francisco.

A sheriff's spokesperson said Thursday afternoon that Mint is 16 years old and that the search is ongoing.

Mint is believed to be in the Tenderloin neighborhood of San Francisco, a law enforcement official familiar with the case said. Mint and Stewart Butterfield are estranged, but officials are concerned about making the family connection public, the source said.

San Francisco police are assisting in the search, and the sheriff's office is working with the child's mother to locate the teen, the agency's spokesperson said.

Mint’s parents could not be reached for comment Thursday afternoon.

Mint, who has brown and red curly hair, is about 5 feet tall, weighs about 100 pounds and has pierced eyebrows, the sheriff’s office said.

Mint was last seen wearing a black sweatshirt, flannel pajama pants and black boots. The teen may have a gray suitcase, the sheriff’s office said.

Anyone with information about the teen's whereabouts is urged to call the Marin County Sheriff's Office at 415-479-2311.

This article was originally published on NBCNews.com