Uruguayan jurist Justino Jimenez de Arechaga, a distinguished defender of human rights in the Western Hemisphere for 35 years, died Thursday in Montevideo after a heart attack.

Mr. Arechaga, 70, was instrumental in the creation of the Inter-American Human Rights Commission, based here, and was one of its seven members from 1968 to 1976. He was forced to step down because the military that seized power in Uruguay in 1973 would not renominate him.

The rights commission's former secretary, Bolivian Luis Reque, noting that Mr. Arechaga served as its president during the critical 1970-74 period, described him as "one of those defenders of human rights who also believes they should apply in his own country."

Under the longtime professor of constitutional law, the commission began a continuing pursuit of rights abuses in the former democracy of Chile as well as by the powerful member of the Organization of American States, Brazil.

During the upsurge of rights violations in 1973 he established the "Arechaga Doctrine," affirming that nations that violate the rule of law have no basis for claiming that victims of rights abuse must exhaust local remedies.

An inveterate campaigner, Mr. Arechaga was a member of a rights sub-commission that investigated violations along the steamy Honduran-Salvadoran border prior to the 1969 "Soccer War."

One complaint led the jurists to a Honduran wayside that turned out to be a house of prostitution. "Our devotion to the cause has brought us this far," said Mr. Arechaga with a wink, "but this is too much."

Mr. Arechaga was a collaborator with Eleanor Roosevelt and other world leaders in the drafting of the U.N. Universal Declaration of Human Rights after World War II.

He is survived by his wife, Lidia, and three daughters, in Montevideo.