A missing US teenager who disappeared more than two weeks ago has been found alive and safe.

A family spokesperson told the news channel KGW on Wednesday (July 9) that Anji Dean, 17, had been returned to her family, but the case was ongoing.

Miss Dean vanished from her home near 192nd in Camas, a city in Clark County, Washington, on the evening of 23 June, sparking fears she had become a victim of sex trafficking. She left behind her wallet, bank cards, her glasses and clothes.

Investigators said they received about 150 phone tips about the girl's whereabouts, as well as information via social media.

The Clark County Sheriff's Office Major Crimes Unit was able to find Dean at a mall in Clackamas County, interview her and reunite her with her family.

"This is an active investigation that includes the crime of human trafficking," said Sgt. Kevin Allais.

After Miss Dean was found, her family posted a message on Facebook that read: "We thank the media, the public and the thousands of people that helped us bring our daughter home."

"We're very, very thankful that she's OK," Dean's mother, Lynda Jorgensen, told reporters.

Earlier on Wednesday, a woman known only as Jennifer, from Milwaukie, Oregon, told KGW she had spent several days with Dean and was trying to help her.

"She said she was in a bad situation and needed to get out," she said.

Jennifer said the teen initially introduced herself as Anji but said she wanted to be called "Daisy". She added that Anji told her people were probably looking for her and she was being forced into things she didn't want to do.

The teen left before she could do anything to help her, Jennifer added.

Before Miss Dean disappeared, she left a chilling message in her diary which read: "If you're reading this, I'm either missing or dead."

Speaking to CNN before the teenager was found, Jorgensen said it was unlikely that her daughter had run away.

"We have no idea where she is or who she's with. She can't be doing this on her own, so we're really, really afraid for her," she said.

On the day she vanished, Miss Dean sent a text message to her boyfriend saying she had got into a difficult situation and that someone was threatening to kill her and her family.

In the hours before she went missing, a neighbour told NBC that she saw Miss Dean getting out of an older, blue car filled with people. The driver was described as "African-American" and aged between 25 and 35, with a goatee beard.

Michelle Bart, the president of the National Women's Coalition against Violence and Exploitation is working with the family and detectives on the case.

"I don't believe she left thinking she was running away. I believe, after speaking with law enforcement and the detective on the case, that we may be dealing with a human-trafficking situation here in Clark County," she said.