SANTA CRUZ, Calif. (AP) _ The father of an 11-year-old university graduate, who once said he wanted his son to win the Nobel Prize by age 20, has been booked for investigation of felony child endangerment, authorities said.

The young scholar, Adragon De Mello, has been placed in protective custody, police said Tuesday.

Officers in this city 80 miles south of San Francisco searched the home of Agustin De Mello on Monday after the boy's mother reported that his father had made threats of violence. Police said they found five loaded handguns and suitcases filled with ammunition.

In an affidavit with the search warrant, the mother, Cathy Gunn, said De Mello had ''a suicide pact with his son in the past'' when Adragon's academic career seemed to be in jeopardy, the Santa Cruz Sentinel reported.

But De Mello, free on $5,000 bail, was quoted in today's Sentinel as calling the suicide-pact charge ''ridiculous'' and dismissing allegations that he is a danger to his son as ''total fiction.''

''I would never consider a death pact with my son. I love him. I live for him,'' De Mello said in a telephone interview with the Sentinel.

De Mello does not have a listed telephone number and The Associated Press could not reach him for comment.

De Mello also said the guns seized from his house posed no danger.

After the search of his home, De Mello was taken to Dominican Hospital for psychiatric examination. He was released Tuesday, arrested and booked at Santa Cruz County jail, said police Sgt. Joe Haebe.

Adragon has received national attention since entering Cabrillo College at the age of 9 and earning a bachelor's degree in mathematics at the University of California at Santa Cruz last spring.

His father has boasted that his son spoke his first words at the age of 2 months and began doing complex science and math as a toddler. The 59-year-old unemployed father has said he wanted Adragon to have two doctoral degrees by the age of 16 and a Nobel Prize by 20.

De Mello was quoted in today's Sentinel as saying his son had been accepted to attend a graduate program on a scholarship at the Florida Institute of Technology.

The newspaper reported Tuesday that Monday's search followed extensive police interviews with Gunn.

Gunn said that she and De Mello never married, but she lived with him and their son until being forced to leave last year, the Sentinel reported.

According to a police report cited by the paper, the 36-year-old Gunn said she recently started legal proceedings against De Mello over visitation rights to the boy. She said she feared De Mello might try to harm her when he received the court papers.

UC Santa Cruz math professor Ralph Abraham, a supporter of Adragon, said De Mello loves his son too much to hurt the boy. ''I have no fears about his care of Adragon,'' he said, although he added that ''enormous stress has affected the father's stability.''