(CNN)The imam says the plea for help came through Facebook: We need food, we're starving.
Siraj Wahhaj said his daughter sent the message to a man in Atlanta who passed it on to him.
"What I do? I said, 'Find out where to send the food,'" the prominent New York imam told reporters Thursday.
As soon as they learned the location, they shared it with police, Wahhaj said, prompting the raid of a New Mexico compound where 11 malnourished children were found on August 3. Nine of them were the imam's "biological grandchildren," he said Thursday.
The missing boy for whom authorities were searching -- a child of the imam's son -- was not found in the raid.
"That's why the police came in, because of information that we gave them," the imam said in his first public comments since his son, also named Siarj Wahhaj, and two daughters were arrested in last week's raid with two other adults.
The imam said he has not spoken with his son since late 2017. Nor had he heard directly from his two daughters, Subhannah Wahhaj and Hujrah Wahhaj, in months, he said. The three adult children had "cut ties" with the rest of their family, he said.
"Those who know them say this is strange, so we want to find out what happened," he said in a news conference in his office at Masjid At-Taqwa mosque in Brooklyn. "I feel bad as a parent that they didn't feel comfortable enough to come to me."
The elder Siraj was the first Muslim to offer an opening prayer before the US House of Representatives, according to the Muslim Alliance in North America. He was also a character witness for convicted 1993 World Trade Center bombing mastermind Omar Abdel-Rahman.
Search for missing boy leads to 11 starving children
New Mexico prosecutors say that at least one of the children found at the compound was being trained to commit school shootings. Beyond that, questions abound about how the family ended up in New Mexico and what happened to Siraj Wahhaj's missing son, Abdul-Ghani.
The boy's mother, who lives in Jonesboro, Georgia, last saw him in November, when his father said he was taking him to the park. Because the couple was married -- she filed for divorce in December -- an arrest warrant was not issued for him until January.
Nearly two weeks after Abdul-Ghani's disappearance, his father flipped a Ford Explorer on Interstate 65 in Alabama. According to a police traffic report on the December incident, a 5-year-old boy and Jany Leveille were taken to a hospital. Six other children were in the car, ranging in age from 3 to 15. The birth date listed for the 3-year-old does not match Abdul-Ghani's birthday.
The search for Abdul-Ghani and his father led authorities to the New Mexico compound. Nine of the 11 children found in the raid were the children of Siraj Wahhaj and his wife, Jany Leveille, who also was arrested, along with Lucas Morten.
The five suspects each face multiple counts of child abuse. Morten is also charged with harboring a fugitive, Siraj Wahhaj, on suspicion of knowing that he was committing custodial interference with Abdul-Ghani.
Abdul-Ghani, whose fourth birthday was on Monday, was not among the 11 children found during the raid. Two days later, authorities found the remains of a young boy whose body has yet to be positively identified.
'We want to find out what happened'
Abdul-Ghani's mother, Hakima Ramzi, said the boy suffers from hypoxic ischemic encephalopathy. He cannot walk and suffers from seizures, requiring constant care and medical attention, she said.
The New Mexico search warrant used to enter the property said investigators had reason to believe Wahhaj planned an exorcism and was denying Abdul-Ghani his medication.
The elder Wahhaj said his son and his wife had become "concerned" with the idea of possessions. But he knew nothing about plans for an exorcism, he said.
He resisted the Taos County Sheriff's characterization of his son's religious beliefs as extreme. But he said his son's behavior could be "extreme" and described him as high-strung, the kind of person who became angry when stopped at the airport by immigration officers, he said.
But "to do something as extreme as this doesn't make sense," he said.
He said his family has been cooperating with law enforcement since his son disappeared with his grandson. That's why he went to police with the message from the compound, he said.
Like others, he wants to know the truth, he said.
"I am feeling a lot of emotions in so many ways," he said Thursday. "We want to find out what happened."