UNITED NATIONS, N.Y.---The dispute between political factions in East and West Pakistan that erupted into bloody fighting in March has left a legal problem for the United Nations to unravel:

What to do about Abu Sayed Chowdhury, a jurist and educator from East Pakistan who was named to the Human Rights Commission before the crisis?

The Pakistani Government last week notified the United Nations that it wanted Justice Chowdhury taken off the prestigious commission. In due course, the Government said, it would offer a successor.

However, Justice Chowdhury has now turned up here, talking to delegates in their offices and telling them his version of the March fighting.

The 51-year-old Judge said during an interview that he would fight to keep his seat on the commission with one aim in mind:

"I want to be able in the United Nations forum to tell the world how the Pakistani Government of President Yahya Khan committed atrocities unparalleled in history against the people of East Pakistan."

Justice Chowdhury says that he now supports the provisional government of Bangla Desh (Bengal Nation) set up by East Pakistani separatists. He is working in Britain to rally support for the cause among the 100,000 Bengalis living there.

His status as a member of the Human Rights Commission is now being studied, say legal experts here. One diplomat predicted that it would lead to a "good fight" in the commission's parent body, the Economic and Social Council, later this year.

There are precedents for individuals continuing to serve on some council commissions after being disavowed by their governments. However, the 32 members of the Human Rights Commission traditionally are regarded as representatives of their governments.

"I still consider myself a member of the commission." Justice Chowdhury declared. He argued that since the council had confirmed his designation, the council would have to decide on his removal and that he was entitled to a hearing.

"It is a fundamental principle of jurisprudence that nobody can be condemned unheard," he said.

Justice Chowdhury was a member of the High Court of East Pakistan for 10 years and also served as vice chancellor of the University of Dacca.

In his talks here he has been particularly bitter that the casualties of the fighting included hundreds of students at his university. He refers to them often as "my children."

As he tells it, he had left meetings of the commission in Geneva and gone to London when news reports reached him that the Government of President Aga Mohammad Yahya Khan had outlawed the Awami League, which was pushing for autonomy in East Pakistan. Next came reports that West Pakistan troops had fired on civilians during the night of March 25, he said.

"When they killed my students and my teachers, I knew I could not go backs" he added. "I could not serve under an administration that murdered in utter lawlessness. As a judge I, could not uphold the rule of law in a country where people are shot while they are sleeping.