While Don King was in town yesterday inviting President Carter to the Muhammad Ali-alfredo Evangelista title fight at Capital Centre, May 16, a participant in the promoter's U.S. Boxing Championships dragged the tournament into a federal court in Houston.

Featherweight Kenny Weldon of Houston charged that Harlan Haas, also of Houston, and George E. Kanter of Riverdale, N.Y., conspired to defraud him of $2500 of a $7,500 purse he was supposed to receive for a tournament bout against Ruben Castillo in Marion, Ohio, March 6.

Weldon lost the bout.

The suit asks for $100,000 in damages.

Weldon contended in the suit that because Hass and Kanter represented to him that be was entitled to only $5,000 instead of the $7,500 that the check by the American Broadcasting Co., which funded the tournament, was made out for, they "wilfully conspired to defraud" him of the $2,500.

Because of that, the suit says, Weldon is entitled to punitive damages of $100,000.

Weldon charged that when he returned to Houston from Marion, he "learned of the fraud perpetrated" and, through his attorney, Lawrence R. Scroggins, demanded that Kanter return the $2,500.

The suit went on to charge that Kanter repeatedly promised to repay the $2,500, but failed to do so.

Scroggins said he tape-recorded a promise on the telephone by Kanter in which he pledged to repay Weldon.

Scroggins said that Weldon called him yesterday and reported he had received a letter from a New York City attorney.

Scroggins quoted Weldon as saying he informed him that Kanter was not going to repay the boxer and, in fact, invited Weldon to file a suit.

Scroggins said he filed the suit about 30 minutes later.

Weldon's suit said that Haas approached him about Dec. 1, 1976, asking whether he was interested in participating in the tournament for a $7,-500 purse.

The suit contends that Weldon later contacted Haas to ask if Jerry Kornele, a boxing associate, might also participate and was told that Kornele could in a package deal that would pay each fighter $5,000.

On the day of the fight, Weldon alleges he was offered a personal check for $5,000 by Kanter, who was supposed to work in Weldon's corner for the fight.

Weldon says he declined the check, returned it to Haas, and later learned from an ABC representative that the network was paying the fighters.

Weldon states that he signed a contract with ABC and that Kanter did as his manager although, in fact, Weldon had not retained him as his manager and that this was the first time Kanter was referred to as such.

Weldon said that ABC offered two checks to Weldon and Kanter, in the amounts of $200 and $7,300, and that Kanter took the $200 check. Weldon contends he was told by Kanter that he would need a total of $2,500 to pay expenses for the fight. Weldon said Haas then wrote Kanter a check for $2,300.

Apparently, Weldon repaid Haas, according to reports in Houston, but that was not made clear in the suit.

It had been previously widely reported that Kanter had agreed to repay Weldon at the urging of James A. Fairley Jr., tournament chairman and chairman of the New York State Athletic Commission.

Kanter could not be reached last night for comment.

Promoter King came to Washington yesterday for a fund-raising luncheon of the Democratic National Financial Council, of which he is a member.

King said he pledged $20,000. He reported inviting President Carter, who was at the luncheon, to attend the championship fight at Capital Centre next month and quoted Mr. Carter as answering, "I don't know if my schedule will permit it but if it does. I will come to your next bout here."

As greeters sought out King to shake hands, he asked them to attend the show.

He said he has not given any thought to the possibility that the Centre bouts may be canceled because of the controversies surrounding his U.S. Boxing Championships, which have been suspended pending an ABC investigation.

Asked if the Ali-Evangelista bout would still go on if ABC decided not to televise it because of unfavorable publicity about the Spaniard's qualifications as a challenger, King said, "That question is so pregnant with possibilities that I'd rather not talk about it."

Besidea the ABC inquiry, charges against tournament figures are being investigated by a federal grandjury in Baltimore. Gov. Hugh Carey of New York is looking into a possible conflict of interest involving Farley. The Maryland State Athletic Commission also plans a hearing of allegations made by heavyweight Scott LeDoux, who fought at Annapolis.