Updated

Police in Texas say the body of a young girl washed ashore in a storage box in Galveston Bay last week could have come from as far away as Europe, but officially ruled out it being British toddler Madeleine McCann, who disappeared in Portugal six months ago.

"We're confident it's not her," Galveston County Sheriff's Department spokesman Maj. Ray Tuttoilmondo told FOX News.

After receiving several tips suggesting that the body may have belonged to McCann, Galveston authorities worked with Interpol, the FBI and Portuguese authorities to eliminate that possibility.

The Gulf Intercoastal Waterway, where the box containing the body was found, is a major commercial port, and Galveston a popular tourist destination with a transient population, Tuttoilmondo said.

"The important thing to consider in this case is that Galveston is a tourist area," Tuttoilmondo said. "We have a lot of commerce going through here," he said.

The Galveston County Sheriff's Department has launched a massive public appeal for help identifying the child, nicknamed "Baby Grace" by police. They have released a sketch of what they believe the child would look like and are offering a cash reward.

According to a forensic dental examination of the remains, she was between 2-3 years-old. She was white, 32 to 35 inches tall and weighing 25 to 30 pounds. She had long blonde or light brown wavy hair, and was wearing a Target-brand pink, flowing skirt, a pink or red shirt and white light-up tennis shoes with purple flowers on them.

Hundreds of tips and leads have poured in from all over the country, Tuttoilmondo said, but so far none of them have helped solve the mystery. Police are also sifting through missing child reports in hopes of finding a match.

"We're still going through known missing person cases. It's a long process," Tuttoilmondo said. "Can I say absolutely she is not a known missing person? No," he said.

"We are getting tips literally from all over the country," he said. "We're going through every single one. This tells me that people are concerned."

Galveston County Crime Stoppers has set up a memorial fund to pay for the little girl's funeral and an account to offer rewards for anyone who helps investigators lead them to the killer. Donations can be made to Galveston County Crime Stoppers.

A fisherman found the girl late Monday night. Her body was inside a blue plastic utility box that washed ashore along the Intercoastal Waterway.

The Galveston County Medical Examiner's Office ruled the child had been dead for at least two weeks and sustained a skull fracture. The cause of death has not been determined but authorities are treating the case as a homicide.

Anyone with information is asked to call the Galveston County sheriff's Office at 409-766-2222, the agency's tip line at 866-248-8477 or any Crime Stoppers organization.

A prayer vigil will be held for the girl Sunday afternoon in Galveston.