Police in Fredericton, N.B. searched the provincial capital for any sign of a missing 10-year-old Quebec girl Saturday after receiving a tip that Cedrika Provencher had been spotted.

A woman told Fredericton police she saw a girl who resembled Cedrika get out of a light-grey minivan that had Quebec plates.

"There was a lady who was a little suspicious of this male and female,'' said Fredericton Police Force spokesman Const. Ralph Currie on Saturday

The witness told police the girl was with a "petite" man about 40 years old, and the two walked to a local shopping mall, Currie told The Canadian Press.

"We can't disassociate this grey van with Quebec plates, but nor can we confirm whether this was absolutely, positively the young girl in question,'' Currie told CP in a telephone interview from Fredericton.

As police investigated the tip, however, it began to seem less likely that the girl in question was Cedrika. Currie said a follow-up interview with the woman revealed she had not seen a picture of the missing girl prior to the sighting. And the girl described by the witness had little in common with Cedrika, Currie said.

"I spoke with the lady myself . . . and there's not a lot striking there, but it's certainly something that we've been following up on,'' he said.

The witness was a woman in her late 60s.

She called police about 10 minutes after the sighting, and officers arrived on the scene soon after, but the van and its occupants were gone by the time police arrived.

"If this van is still in the area, we would certainly see it,'' Currie said.

Recently, Quebec police released descriptions of a car and man they believe are connected to the disappearance of the girl, giving her father hope that his daughter may be found.

"We're talking about something concrete," Martin Provencher told reporters on Thursday. "It gives me hope. It's progressing."

Police have told the public to be on the lookout for a white man with brown hair who has access to a red four-door Acura, likely manufactured between 2002 and 2004.

"This man could be your son, your brother, your uncle, your father," police spokesperson Sgt. Francois Dore told a press conference.

Police said they have received 4,000 tips since Cedrika went missing five weeks ago during a bike ride not far from her Trois-Rivieres home.

They said they will need more detailed information before they put out a composite sketch of the suspect. However, police were able to give the public some details about who they are looking for.

The man is described as:

• 30 to 40 years old

• White male with light brown hair

• Medium build and average height

• French-speaking

• Wearing sandals, Bermuda shorts and a short-sleeved T-shirt the day Cedrika went missing

The car is described as a four-door red Acura with a beige interior and chrome door handles.

Police warned the public that the man may have altered his appearance or changed his car since he was last seen. Nonetheless, they said they have warned border authorities throughout Canada and the United States.

Cedrika went missing July 31 around 8:30 p.m. Neighbours told police the little girl asked them for help looking for a lost dog that didn't belong to her.

After she went missing, several other young girls told police they too had been approached by a man asking them for help finding his lost puppy.

At the news conference, police told reporters they didn't release the descriptions earlier because they had to be "very sure" about what they were looking for.

Investigators repeated that they believe Cedrika is still alive because they have no information telling them otherwise.

With files from The Canadian Press