A person who claims to know a missing Texas soldier raised questions about his mental state Wednesday, saying Pfc. James Gonzalez is "disturbed" and has called him several times since his disappearance last week.

The source, who spoke to FOX News on condition of anonymity, said Gonzalez recently had been bragging about a promotion first to lieutenant and then to major, was spotted driving a new Mercedes 300 and boasted he'd bought a big house in Laredo, Texas.

The latest claims cast further doubt on whether the 24-year-old Army private's disappearance is an abduction for $100,000 ransom — as the family says authorities have told them — or a hoax.

Gonzalez was last seen July 11 at his mother's house near Corpus Christi, when he told relatives he was heading with friends to Laredo — a town bordering Mexico where he frequently traveled, according to his older brother.

On July 13 — the day Gonzalez was to return to base — his commander called looking for him, J.C. Gonzalez told FOX News on Wednesday.

The same day, the FBI phoned the family telling them James had been kidnapped and was being held for ransom, his brother said.

The caller demanded $100,000 and the withdrawal of all troops from the border, J.C. Gonzalez told FOX.

"We received a phone call from the Army asking if we had heard or seen from James," he said. "A few hours after that we received a phone call from the FBI that he had been abducted and there was a ransom for him. ... That's what's being told to us."

He said his brother was familiar with Laredo and had not mentioned any plans to cross into Mexico, directly across the Rio Grande. He said authorities have been tight-lipped on any developments in the case south of the border.

"That's being kept from us," Gonzalez said. "They say they're working on intelligence from people in Mexico."

The family has been told that for the past week, James Gonzalez's cell phone has gone straight to voicemail, he has not logged into his MySpace Web page and authorities have not been able to track his car, a 2006 BMW, which was fitted with a tracking device.

The Army and the FBI are confirming little about the case. The FBI is referring questions to the Army, which is leading the investigation.

LIVESHOTS BLOG: What Happened to Private Gonzalez?

If Gonzalez was going to take off, "he would have told somebody," his brother told The Associated Press Tuesday. "It's not like him at all."

Gonzalez was awaiting trial this fall on misdemeanor charges stemming from an argument with his girlfriend. His brother said that situation was being handled and would have been no reason for him to disappear, and dismissed the theory that James would have fled because of the dispute — which involves allegations about rocks thrown from a vehicle.

"That's little stuff. That's misdemeanor charges that will either be dismissed" or carry a minor fine or other light penalty, J.C. Gonzalez said on FOX.

Christopher Grey, chief public affairs officer for the U.S. Army Criminal Investigations Command in northern Virginia, said the Army was cooperating with local, state and federal law enforcement agencies in the search for Gonzalez.

Grey said the Army would not discuss details of the case, including whether it received a ransom call. The Army had issued an advisory in the border region asking people to be on the lookout for Gonzalez and to contact local law enforcement with information on his whereabouts, Grey said.

The family says it has been frustrated by the Army's response.

"We don't feel the Army is taking it as seriously as we are," J.C. Gonzalez told the AP.

James Gonzalez's decision to join the Army about a year and a half ago surprised his family, but they supported the decision, according to J.C. Gonzalez. It seemed to be a good change for him.

"He was pretty happy," his brother said. "He had a house, a car and had taken that step to manhood. He was enjoying himself."

About 575 National Guard troops remain on the border, but thousands who had been patrolling the area withdrew last year.

FOX News' Maggie Kerkman and The Associated Press contributed to this report.