Three-year-old leukemia victim Chad Green, snatched from his home here by his parents to escape a state court order barring Laetrle treatments, is receiving the controversial substance along with chemotherapy by a private Mexican cancer clinic.

Gerald and Diana Green, embroiled in a two-year legal skirmish with their son's doctors over the proper method of cancer treatment, secretly flew to Tijuana with the boy Wednesday night in violation of the ruling retaining state control over Chad's medical care.

Chad's court-appointed attorney, John Wyman, today filed civil contempt charges against the parents, who may also face kidnaping charges. The Justice Department will not move to extradite the family until state criminal charges are sought, U.S. Attorney Edward Harrington said.

"We are not really looking to get the parents; it was a desperate move," said Massachusetts assistant attorney general Jonathan Brant. "Our only real interest is for the welfare of the child."

Chad, whose blood condition is currently in remission, is being poisoned by the cyanide in Laetrile, and, if the treatment continues, "he may well go blind, deaf and be unable to walk," said Dr. Victor Herbert, a New York hematologist who testified here last week.

But the young parents, self-described born-again Baptists, are convinced that their child's only hope for a cure is an unorthodox "metabolic" therapy: Laetrile, massive doses of vitamins A and C, enzyme enemas and a diet of goat's milk, fresh vegetables and raw fruit -- and faith in the will of God.

"We had to leave because the state was trying to control what Chad could and could not eat; they're denied us all of our parental rights and freedom of choice," said Gerald Green, 28, in a telephone interview from the Del Mar Clinic in Tijuana where Chad received a battery of diagnostic tests today. Laetrile is legal in Mexico.

The child's treatment is now in the hands of Dr. Ernessto Contreres Rodriguez, 63, who runs a 50-bed hospital which is always full, a clinic, and a hotel with 44 rooms and six suites costing between $14 and $21 a day.

The Greens are staying in a small room with kitchen facilities at the Del Mar Hotel -- the temporary home of dozens of other Americans who have pinned their last hopes for survival on the controversial substance Laetrile, an extract of apricot pits or bitter almonds which the U.S. Food and Drug Administration has declared to be neither safe nor effective.

The Laetrile is produced by the KEN Laetrile factory, owned by Contreres, which has its only outlet at Del Mar, though some of it has reportedly filtered into the United States.

The Del Mar facility is located near the ocean across from a modern new bull ring. Outside the clinic, a 10-foot mural depicts a muscular man battling a giant crab, the Zodiac cancer symbol.

Clinic patrons pay up to $700 for three weeks worth of Laetrile, X-rays, laboratory tests and once-a-week visits by a doctor. The Greens, in debt despite contributions of about $5,000 from sympathizers across the country, said they were unsure of the cost of their stay.

"It doesn't matter what it costs," said Gerald Green, a welder. "It's Cahd's life that's at stake and I'll go to the far side of the moon to do what I can for Chad; if I die being in debt, then at least I can tell myself I've done everything in my power to help my son."

"Del Mar is just another Laetrile ripoff operation," said Herbert, who runs the hematology and nutrition laboratory at Bronx Veteran's Administration Hospital in New York. "And Chad could die just like Kimberly Cox nearly died."

In a case similar to Chad's, Kimberly, seven years old at the time, was taken to Contreres' clinic after fleeing a court order in Milwaukee. After two weeks at the Del Mar Clinic, she was rushed to University Hospital in San Diego bleeding profusely from the nose -- a condition sparked by relapse of leukemia which destroyed the ability of her blood to clot. Under conventional therapy, Kimberly's disease later went into remission.

The Greens fought against chemotherapy in court suits last year, claiming its side effects caused Chad to "act like an animal." They later acceded to the treatment, providing they could administer Laetrile and organic foods. The Greens say they will pursue their fight to the U.S. Supreme Court.