(CNN) The remains of a young boy were found on a compound in rural New Mexico where 11 emaciated children were discovered last week, authorities said Tuesday.

But it is unclear whether the remains uncovered Monday are those of a missing Georgia boy, Abdul-Ghani Wahhaj, who was nowhere to be found after authorities stormed the complex on Friday. The boy's father was suspected of abducting him late last year from Clayton County, Georgia.

Taos County Sheriff Jerry Hogrefe said the positive identification of the remains is pending an autopsy.

"We discovered the remains yesterday," the sheriff said, getting choked up, "on Abdul's fourth birthday."

The boy's father, Siraj Wahhaj, was arrested Friday along with his sisters Hujrah Wahhaj and Subhannah Wahhaj after authorities raided the compound. The siblings and two other adults also arrested -- Lucas Morten and Jany Leveille -- are accused of keeping the children in an underground trailer with virtually no food or water.

New Mexico authorities had suspicions that the father and son may be at the compound after learning in May about the abduction, the sheriff said. But authorities didn't have enough evidence for a search warrant, he said. Surveillance of the property didn't identify the pair there, the sheriff said.

The "breaking point for us" in the search for Abdul-Ghani came last Thursday, when New Mexico authorities received a tip about possible starving children living on the compound, the sheriff said. He said he felt investigators had enough probable cause to put in an affidavit for a search warrant.

The sheriff said authorities learned more details after the raid and returned Monday with a good idea of where to search for Abdul-Ghani.

Abdul-Ghani's mother, Hakima Ramzi, could not be reached after authorities announced the discovery of the remains.

The boy's grandfather, Imam Siraj Wahhaj is "devastated that those remains could possibly be those of Abdul-Ghani," according to a spokesman.

"We don't know whether those remains are those of his grandson," said the Imam Al-Hajj Talib 'Abdur-Rashid, head of the Muslim Alliance in North America.

'I haven't seen my son in nine months'

Hours earlier, Ramzi told CNN she knew her husband wanted to rid their then 3-year-old son of his medical problems. But she had no idea he'd disappear with their son for nine months, only to be found across the country with 11 other children living in squalor

The younger Wahhaj, 40, and the four other adults found at the compound have been charged with abuse of the 11 children found in a filthy, makeshift compound.

Lucas Morten

Morten was charged with harboring a fugitive. The five are set to appear in court on Wednesday.

"I haven't seen my son in nine months," Ramzi said on Tuesday.

"My husband said he was taking Abdul-Ghani to the park, and didn't come back. That was in November 2017. When I would ask him where he was, he said he was on his way, he was coming soon, he was just keeping him for the night. But I haven't seen him since then."

She said Abdul-Ghani has hypoxic ischemic encephalopathy . "He cannot walk and suffers seizures and requires constant medical attention," Ramzi said.

An arrest warrant affidavit for Wahhaj said the mother claimed Wahhaj "wanted to perform an exorcism" on the child because he believed Abdul-Ghani was possessed by the devil.

But Ramzi clarified to CNN that her husband said he was planning to perform a ruqya -- an Islamic practice involving prayer that is believed to help rid a body of illness.

"It's not an exorcism. That was a translation issue in the court," Ramzi said. Wahhaj "just wanted to pray for Abdul-Ghani to get better."

Suspect's father is a controversial religious leader

Wahhaj's father -- Siraj Wahhaj -- is a prominent and controversial New York imam.

The imam was the first Muslim to offer an opening prayer before the US House of Representatives, the Muslim Alliance in North America said. He was also a character witness for convicted 1993 World Trade Center bombing mastermind Omar Abdel-Rahman.

In a January Facebook post, Imam Siraj Wahhaj called for the safe return of his three children and 12 grandchildren.

On Tuesday, Imam Siraj Wahhaj said his son and two of the women arrested -- Hujrah and Subhannah Wahhaj -- are his children.

"I want to first express my gratitude for law enforcement for helping to locate my family," the elder Wahhaj said. "My immediate concern is the safe return of Abdul-Ghani to his mother."

The father was spotted on his way to New Mexico

In December, days after Ramzi reported her son missing, the younger Wahhaj was involved in an accident in Alabama, according to a police report. The SUV contained seven children -- but none of the children was listed with Abdul-Ghani's date of birth.

Siraj Wahhaj is accused of fleeing Georgia with his young son.

The SUV was registered to Leveille, who was also in the vehicle. She would later become one of the five adults arrested at the compound in New Mexico.

But at the time, Alabama police didn't hold the group after the traffic accident. The group told police they were headed to New Mexico to go camping, and continued on their way.

Even though young Abdul-Ghani was reported missing, there was no child abduction warrant against Wahhaj because he was married to his son's mother -- meaning they both had equal custody of the boy, Clayton County police said.

But a juvenile court judge eventually issued an arrest warrant to question Wahhaj after he failed to let the mother know where Abdul was.

Deplorable living conditions

The three Wahhaj siblings, Leveille and Morten eventually gathered in the remote New Mexico community of Amalia. There, they kept the children in squalid conditions, authorities said.

"The only food we saw were a few potatoes and a box of rice in the filthy trailer," Hogrefe has said.

The children were found in a trailer with no plumbing.

His officers helped execute a search warrant on the compound after receiving the message last week that was apparently forwarded from someone at the compound: "We are starving and need food and water."

The children looked like "Third-World country refugees" with no fresh water, no shoes, "and basically dirty rags" for clothing, according to the sheriff.

"We all gave the kids our water and what snacks we had -- it was the saddest living conditions and poverty I have seen," Hogrefe said.

An aerial view of the compound shows its remote location.

The children were taken into protective custody and later turned over to the New Mexico Children Youth and Families Department.

The state agency said it planned to file a petition with the court to maintain custody of the children, according to Monique Jacobson, cabinet secretary for the department.

Over the weekend, Jason Badger and his wife Tanya , whose land the compound was erected on, said they went back to the property to look for Abdul-Ghani.

They had seen a young child that they said resembled the boy two times, in January and February, the couple told CNN.

The Badgers said they knew he hadn't been found after the raid.

Badger said the couple found what he described as two breathing machines. One machine had "a little bitty mask," he said.

"Clearly, you could tell it was made for a child," he said.