U.S. efforts to extradite and prosecute foreign drug traffickers have been severely handicapped by legal and social problems encountered by foreign witnesses brought here to testify, according to a report by the House Government Operations Committee.

The report, based on testimony from federal witnesses and former federal prosecutors and officials of the federal witness protection program, recommended immigration laws be changed to extend permanent resident status to any foreign witness "with information critical to federal prosecutors."

The issue has assumed new importance as prosecutions of Latin American drug traffickers have accelerated, putting pressure on an already overburdened Witness Security Program not well equipped to handle Spanish-speaking witnesses who often bring large families with them.

The report recounted the suicide of one witness's brother-in-law because of apparent mishandling of his case and a widespread concern that witnesses will refuse to cooperate when they learn how difficult it is to become legal U.S. residents after they testify. Howard Safir, former associate director for operations of the U.S. Marshals Service, told the committee one witness had to shed his protective new identity in order to remedy his immigration problems. "This is not a signal we want to send out to potential informants who have vital information," Safir said.

Verne Jervis, a spokesman for the U.S. Immigration and Naturalization Service, acknowledged difficulties securing resident status for witnesses but said "many of them do apply for and eventually receive it."

Some federal officials anticipate resistance to granting permanent status to witnesses who often have been drug traffickers themselves. Some witnesses may also be tempted to embroider their stories in hopes of proving their value to prosecutors, one official said.

According to the report, based on an internal Justice Department review and a hearing by the House subcommittee on government information, justice and agriculture, the portion of the Marshals Service's witness cases that are narcotics-related increased from one third in 1983 to 80 percent today. The number of foreign witnesses in the last three years was 92 percent higher than the previous three-year period.

Under current immigration law, a witness may seek permanent resident status only if he has U.S. relatives or an employer willing to apply on his behalf, or is eligible for political asylum. But asylum applicants "cannot have a previous record of criminal behavior," the report said, which rules out many witnesses to drug transactions.

If relatives want to petition on behalf of a protected witness, the report said, "they must know a potential witness' new name or relocation area" which under current guidelines "is not possible."

The report recommended the Justice Department determine if some promises of resident status for potential witnesses have not been kept and asked that the Marshals Service receive more resources to care for witnesses and their families.

The report said Johnny Crump, whose testimony helped prosecute Cuban officials dealing in drugs, dropped out of the witness program after one of his daughters was forced to pay nonresident university tuition and another was barred from a flight attendant job because her father's lack of resident status prevented her from getting a passport. The report said Arturo Jaramillo, brother-in-law of Max Mermelstein who testified against the Medellin cocaine cartel, became depressed and killed himself after being relocated in Memphis, Tenn., where his Marshals Service contact spoke no Spanish and his poor English caused him to fail a driver's test.

Rep. Robert E. Wise Jr. (D-W.Va.), chairman of the subcommittee, said he has introduced a bill to grant permanent resident status to up to 100 foreign witnesses a year. "Unless we deal now with the immigration problems facing key narcotics witnesses," he said, "we will have great difficulty securing their crucial cooperation."