A 12-year-old girl who vanished after being dropped off to meet a friend apparently lied and was actually going to see someone she'd been communicating with online.

The family of Brooke Bennett believes the girl made up the story of accompanying a friend to visit a sick relative in the hospital, police said Thursday.

Instead, she was apparently planning to meet an unknown person she had been in touch with on the Internet. Vermont's FOX 44 reported it may have been someone she had met on the social networking site MySpace.

The Vermont State Police issued an Amber Alert Thursday in their search for the girl, who hasn't been seen since Wednesday morning.

Brooke, of Braintree, was reported missing around 9 p.m. Wednesday, about 12 hours after her uncle dropped her off at a convenience store in Randolph, Vt.

She told family members she was going to meet a girlfriend and then go to visit a sick relative of the girlfriend at a hospital, according to Vermont State Police Capt. David Covell.

"It is the family members' opinion that that was a ruse to the family to get to that location," said Covell. "There's been no interview conducted that supported that that was a legitimate meeting."

Surveillance camera footage from the Cumberland Farms store showed Brooke being dropped off by her uncle and cousin, who drove off, according to Covell.

The footage showed Brooke walking away from the store by herself, he said. That was the last time she was seen.

A family member searching for her Thursday in Brookfield — near her uncle's home, where she spent the night — found items belonging to her near Route 65 that were similar to what she had been wearing, prompting an intensive search by police and dogs in the area of the Floating Bridge.

In the Amber Alert, police said they had no information about a suspect or any vehicle.

Police have not identified the person she was communicating with, but Vermont State Police computer experts were analyzing the computer in a bid to learn more, authorities said. Police said they don't know if it was a woman or a man.

Vermont State Police divers will begin searching Sunset Lake on Friday, according to Covell. About 14 detectives are currently working on the case, he said.

The girl's father, James Bennett, 41, of Bethel, said he hadn't seen his daughter in two weeks and that she lives with her mother.

"I'm sitting here waiting for a phone call, hoping it's good news. This is a very difficult time," Bennett said.

The girl, who just finished seventh grade, is described as 4-foot-11 inches tall, 98 pounds, wearing blue jeans, a pink sweater and white sneakers with pink lettering. Police won't say what items were found by the relative.

Anyone with information about Brooke's whereabouts is asked to call the state police at (802) 234-9933.

Click here for more on this story from FOX 44.

The Associated Press contributed to this report.