The Libyan leader broke into laughter during the interview, appearing to enjoy Libya's attempt to dabble in American politics and claiming, with a touch of pride, that Libya had managed to accumulate influence at the highest American policy-making levels.

He was asked about an allegation here last week by Ahmad Tabib, who has helped arrange Billy Carter's visits to Libya, that Mr. Carter's party had taken a valuable gift, estimated to be worth as much as $50,000 for President Carter. Gifts for Guests Held Normal

''I have no knowledge of gifts, financial assistance or loans because I don't really get involved in these ordinary matters,'' Colonel Qaddafi said. ''But I should say that, as far as we are concerned, we have no reservations at all about giving gifts to our guests or sending gifts to their relatives. This is not a big thing. Quite the contrary, it is considered part of our obligations as hosts and very much part of our traditions. It is quite proper to give someone a present for his relatives, for his family.''

The Libyan leader said he did not meet Billy Carter on his two visits because of the pressure of official busines, but noted that he would be glad to meet the President's brother if he came again.

Colonel Qaddafi portrayed the relationship with Billy Carter as nothing out of the ordinary, saying that he had received American delegations of blacks, academics, students and Americans of Arab descent. He defended the $220,000 loan. 'The Money Is Not Stolen'

''The money is not stolen,'' he said. ''It is not a bribe. It is purely a commercial transaction, a business affair, or a loan.'' When asked which of these terms best described the money, he said: ''Of course, it is a loan and it will be repaid. It is a loan related to business. Is it forbidden to do business with Americans? We have American oil companies here that are doing business all the time - why not question them? American banks are filled with Libyan dollar deposits on loans. Why not put them on trial, too? Why only Billy Carter? Why are they hounding Billy Carter?''

When asked whether Billy Carter's business deals involved oil purchases, Colonel Qaddafi said: ''Maybe, probably. All the details on this are with the Foreign Relations Office.'' He said questions regarding the repayment of the loan could be directed to that office, which is headed by Ahmad al-Shahati, who is Libya's foreign affairs chief.