Concern about the well-being of political detainees and about South Africa's badly bruised image abroad has prompted increasing calls from both the Afrikaans and English-speaking communities for a change in laws allowing detention without trial.

There has also been open criticism within the ruling National Party of the "thoughtless remarks" made by some government officials when Steve Biko, leader of South Africa's black consciousness movement, died in police custody Sept. 12. A few days after Biko's death, Minister of Justice and Police Jimmy Kruger said that Biko's death "left me cold." Another politician said in a speech that he would have killed Biko.

Although there have been protests about detention laws in the past, it is only since the inquest into Biko's death in November that appeals for modification of the law and the way it is applied have come from Afrikaner editors, academics and lawyers.

Biko died of severe head injuries that are widely believed to have resulted from a beating while in police detention. An inquest found no one reponsible for his death but there was testimony that after sustaining his head injuries, he received inadequate medical attention, lay on a urine-soaked mat while chained to a window grill and was driven naked for 750 miles in the back of a Landrover some hours before he died.

"A large number of people, until Biko's inquest, had little idea of what was going on," said one concerned lawyer. "The legal profession was horrified."

Biko, like many other detainees under South Africa's 1967 Terrorism Act, was held incommunicado. The government refuses to say how many other political prisoners it has, but the South African Institute of Race Relations has compiled a list of 714 detainees and estimates that the actual total is close to 800.

The most recent call for changes in the detention laws came last week when a four-man delegation representing the country's lawyers met with Kruger.

"Our visit was prompted by concern not only for the safety of the detainees but also by concern that recent events have considerably lowered the reputation of the South African legal system in the world," said Douglas J. Shaw, who led the delegation.

Kruger made it clear that by discussing the matter be was not admitting "there have been any malpractices with detainees," according to a press release, which described the talks as "fruitful."

Leading Afrikaans newspapers which support the ruling party have also called for revision of the detention laws. The Sunday paper Rapport commented that "it is not only opponents of the government that have serious doubts about detention without trial and the extent of it. It is obvious that people cannot just be continually locked up."

Another call to change the detention laws and to bridle the powers of the police came in a declaration from one of the citadels of Afrikaner learning, Potchefstroom University. Students and professors signed it, including the head of the university's department of constitutional law, Johan van der Vyver.

In a related development, Connie Mulder, the powerful minister who administers the complex laws that regulate the lives of blacks here, said he would approach Kruger about releasing some of the top leaders of the black community of Soweto who were detained in October.

Most observers are skeptical of any real change in the detention laws in a county where habeas corpus does not exist. But in parliament recently there was evidence of unhappiness among National Party members about South Africa's foregin image.

When the popular Kruger rose to answer the opposition's attack about his the usually rambunctions Parliament.

A few days later, Fthe usually rambunctions Parliament.

A few days later, Foregin Minister Roelof (Pik) Botha spoke out forcefully about how "thoughtless remarks" about Biko's death had done immeasurable harm to South Africa's image abroad. He did not mention Kruger by name, but the audience was certainly thinking of him. The Afrikaner newspaper, Die Vaderland (The Fatherland) congratulated Botha for his speech and said, "We hope that nationalists - and this concerns particularly certain public representatives of the governing party - will take Mr. Botha's admonition to heart."