South African Foreign Minister Pik Botha in his most outraged attack on Carter administration policy accused the United States yesterday of "moral hypocrisy"

" . . . People in white houses," Botha said, directing his indignation at the American presidency, "should not throw little stones. Let the United States achieve complete equality before pontificating to me from a high moral forum."

This criticism, the sharpest so far about U.S. policy in Africa from the stronghold of white minority rule, was reported in a Cape Town interview with United Press International reporter John Platter.

At the same time, Botha made a bristling response to charges that one of South Africa's Washington-based envoys breached diplomatic protocol last week by speaking out against Sen. Dick Clark (D-Iowa) in the legislator's home state. Clark, chairman of the Senate Foreign Relations Subcommittee on Africa, is up for reelection.

Botha, however, sweepingly surpassed the indirect criticism of Clark attributed to the South African Embassy economics minister, Jan H. Van Rooyen, during a visit to Iowa "to enhance trade" with South Africa. Botha's comments were made just before his Foreign Ministry summoned the U.S. Embassy's charge d'affaires, Harvey Nelson, to respond to a U.S. complaint made Wednesday.

"As regards Sen. Clark," Botha said, "I have to point out that he is not only constantly meddling in the internal affairs of South Africa, but that is actively engaged in actions which are aimed to cripple South Africa economically.

"He's not concerned about the sufferings of black people should his plans be carried through."

Botha said he and Clark participated in an American television interview on Aug. 29, 1976, "and at the end of the program I said to him: 'I don't believe that the voters of Iowa have given you a mandate to seek my country's genocide, demise and ruin."

State Department press spokesman Hodding Carter countered that Botha's statement "obfuscates . . . a complaint," namely "the unwarranted intrusion into part and parcel of (American) politics by a representative of the South African Embassy in this country."

"The right of Pik Botha to say he disagrees with our policies," Carter said, "is quite another matter - or our to say we disagree with their policies."

Botha became noted for blunt outspokenness as South Africa's ambassador to Washington (1975-77). At present, South African sensitivities are especially inflamed by international denunciation of its apartheid, or racial separation, policy by United Nations condemnation of its recent para-troop raid into Angola, and by domestic charges of scandal over the use of secret South Africa funds to influence public opinion in the United States and other countries.

Botha made it unmistakably clear in his interview with UPI that his country is hardly in an apologetic mood toward the United States about Sen. Clark or anything else.

Sitting behind a desk under a blue-and-yellow flag inscribed "Don't Tread On Me" (apparently a copy of the 1775 American flag with the same motto), Botha inveighed against Carter administration policy in Africa. American officials, he said, "should eliminate their own sophisticated, vicious forms of racial discrimination before hypocritically preaching" to South Africa.