The same day that Sports Minister Piet Koornhof was stating on television that racially mixed sports teams were not illegal in South Africa, six policemen swooped on a soccer team near Pretoria threatening its eight white and six black members with arrest for breaking the law by playing together.

Such is the difference between principle and practice when it comes to South Africa's "new" sports policy aimed at eliminating racial barriers in sporting activities. The confusion is caused mainly by the government's hesitation to spell out exactly what the sports policy means.

This week Koornhof stated explicitly for the first time that "no legal permission is needed" for racially mixed clubs or games. In addition, the moderate that he was undertaking changes in South Africa's liquor laws which would allow sports clubs to integrate their bars and restaurants by applying for "international status."

The liquor laws, which prohibit whites and blacks from drinking together, have presented one of the major obstacles to the integration of sporting clubs.

Both English- and Afrikaans-language newspapers welcomed the Korphof announcement, giving it prominent display. It is sure to give an impetus to the integration of sporting activities, and sports club presidents gave generally welcomed the move.

But political observers in Cape Town report that the announcement has stirred the ire of right-wing elements in the ruling National Party who called it a "total departure from policy." Some were predicting a major row in the party between these hard liners and the more moderate group that favors eliminating racial discrimination at a faster pace.

The sports minister called his remarks a "clarification" of the "new" sports policy which was first set forth in September 1976. He addressed them to a visiting four-man delegation from the International Tennis Federation that recently ended a 10-day trip here to monitor South Africa's progress in integrating sports.

The delegation, much like the South African public, found the sports policy confusing and unclear and asked Koornhof to state it more explicitly. His answer was to make it clear once and for all that racially mixed sporting events do not conflict with South Africa's laws setting out residential segregation.

Known as the Group Areas Act, this legislation carves South Africa into white and black areas and prohibts integrated activities. Implementation of the new sports policy has been hindered by this set of laws.

For example, organizers of sporting events have had to apply for a special permit for each interracial match in order to allow racially mixing spectators. Koornhof said sporting bodies at the national and provincial level now will be able to get a blanket permit at the beginning of each sporting season for mixed crowds.

The government granted the first such permit to the multiracial National Professional Soccer League last week.

This requirement to request permits has rankled many sports leaders who object to having to ask for permission to play against a team of a different race. "We abhor applying for permits," said one Indian sports leader. "We are South Africans, no aliens."

Koornhof also promised the ITF delegation that "early steps" would be taken to see that government sporting subsidies would be given out fairly to all groups. He said his National Department of Sport "will endeavor to use its influence with local authorities to provide sport facilities to all population groups according to their needs."

Getting local authorities to accept the clarification on his sports policy will probably be Koornhof's biggest task. The raid on the Pretoria soccer team this week highlights the problem.

Composed of blacks and whites employed by the same firm, the team is one of 12 which played in a multiracial league last season without incident.

Two of the players told how three police vans and six policemen drove across a rugby field where a game was in process, approached their team and ordered the six blacks into the back of one of the vans. Meanwhile, another team with two "colored" (mixed race) members arrived at the municipal park's field and the "coloreds were chased away" and told not to play with whites, the players said. The blacks were ordered out of the playing area.

Two white members of the team said later, "we were very annoyed, embarrassed and inconvenienced . . . playing with our black colleagues improves race relations within our company."

The police, who said they had acted on a complaint, wanted to charge everyone with violating the Group Areas Act, but were persuaded to issue a warning instead.