One Tuesday afternoon last month, Klaus Barbie took time from his routine in this Andean capital to pay an unsolicited visit to the Bolivian government comptroller's office.

His business was relatively simple: to pay a six-year-old, $10,000 debt, his sole legal quarrel with Bolivia's new democratic government.

Barbie approached officials and announced he was prepared to pay. But the Bolivians insisted that the dollar debt be converted to Bolivian currency at the official exchange rate, then widely ignored. Barbie argued for a fairer price.

The result, government officials here say, was that irritated bureaucrats in a minor government agency placed one of the most wanted Nazi war criminals under arrest, to the surprise of the government leadership here and the French and West German diplomats who for years had sought Barbie's extradition.

With that petty argument and ad hoc detention, events were touched off that led to Barbie's celebrated imprisonment in France on charges of crimes against humanity--and an ongoing controversy in Bolivia about the methods and motives of a weak government's sudden action.

In Lyons, France, Barbie was told yesterday that he faces trial in at least eight cases involving shooting, torturing and deporting hundreds of Jews and French resistance fighters.

United Press International reported that investigating Judge Christian Riss met with Barbie in his solitary confinement cell at St. Joseph's Prison to inform the former Gestapo chief of the specific charges of "crimes against humanity." These involve Barbie's role in the deaths of 294 French citizens and the deportation to Nazi death camps of 650 others.

Riss was accompanied by Barbie's court-appointed lawyer, Alain de la Servette, who said that Barbie, 69, had "aged considerably in a very short time and refuses to accept his enforced isolation."

Barbie's summary expulsion by the struggling, left-of-center government of Hernan Siles Suazo has won Bolivia wide praise from European governments at a time when the country desperately needs aid. Gratified French officials say that in addition to an aid package planned before the expulsion, they intend to "lead a campaign for Bolivia in Europe," in the words of one.

In Bolivia, however, Barbie's expulsion is not such a simple issue.

Even as the government has continued to broadcast reports on state television about Barbie's crimes and European gratitude, leading democratic politicians and newspapers have questioned the government's hasty abandonment of an extradition case in the Supreme Court.

The uncertain legality of the government's later actions, including holding Barbie incommunicado for 11 days and expelling him on the grounds that his 25-year-old Bolivian citizenship was not valid, have led many Bolivians to conclude that the government acted precipitately in the hope of quick political gains.

"Almost everywhere it is said that turning Barbie in tends to fortify the ties of friendship with France," the left-of-center newspaper Presencia editorialized. "In other words, Bolivia presents itself in the not very complimentary role of somebody who turned somebody in for a reward."

Bolivian officials say they intended all along to expel Barbie.

"The right moment came with his arrest because he was in our hands," said Foreign Minister Mario Velarde Dorado. "He is a foreigner completely unwanted in Bolivia. If we released him, we would have had to arrest him again, and he is a dangerous man."

Political leaders here add, however, that Barbie's arrest in January happened to coincide with the Siles government's most severe crisis in its four months.

Those difficulties and France's strong influence, they say, caused the reversal in the policy of waiting for a court decision and an equally worldly-wise decision to send him to France rather than West Germany.

Siles' government took office in October with many reasons to expel Barbie.

For 20 years after coming to the country in 1951, the former Gestapo commander apparently lived quietly under the alias of Klaus Altmann, managing a lumber mill in northern Bolivia and obtaining citizenship under his false name in 1957.

After his discovery by French investigators in 1971, however, Barbie was linked to Bolivian military governments and paramilitary movements. Officials now charge that he was connected to cocaine trafficking interests, and other reports say he advised military leaders on torture and brokered arms deals, although no proof has ever surfaced.

Soon after taking office, Siles announced in an interview that Barbie would be expelled if European governments requested it. Yet, for almost four months, the Bolivians took no action.

Diplomats interested in the case were told, instead, that the government intended to wait until the Supreme Court ruled on an extradition request filed by West Germany in May 1982. The court had rejected such a request by France in 1974.

Then, only days before Barbie's arrest on Jan. 25, the government's leading minority coalition party, headed by popular Vice President Jaime Paz Zamora, left the government after a dispute with Siles, forcing the president into an emergency reorganization of his Cabinet.

Among other issues, Paz's party charged that Siles' interior minister had failed to act against extralegal right-wing paramilitary groups and cocaine traffickers--elements to which Siles himself had linked Barbie publicly.

At the same time, the governmental crisis forced the cancellation of trips by Siles to France and Paz to West Germany.

Government officials and congressmen here concede that Bolivia's new democracy is unlikely to survive economically without support from abroad. Siles' administration inherited an empty treasury along with a$5 billion foreign debt on which no payments had been made in more than a year.

Only three days after Siles and Paz would have arrived in Paris and Bonn, Barbie turned up at the comptroller's office, apparently eager to settle any disputes that could have given the government an excuse to arrest him. Eleven days later, he was on his way to France.

"It was a political decision," said Paz, who remains vice president. "They had intended to wait for the court, but they needed to do it in that moment--both for external and internal political reasons."

But the process of arranging a departure dragged--largely, according to sources, because of second thoughts by Bolivian officials over the questionable legal measures.

Then, say sources here, pressure from France's Socialist government helped decide the quick expulsion. Unlike West Germany, France offered Bolivia an easy method of expelling Barbie to Europe through its colony of French Guyana--eliminating the problem of stopovers by Bolivia's military transport plane in third countries.

More importantly, France was on the verge of agreeing with Siles' government on a major package of economic aid--including treasury-to-treasury grants. Officials here say that the package was to have been announced during Siles' visit to France, and the announcement was postponed when the trip was called off.

Now, officials say that the aid package will be announced with fanfare during a rescheduled trip in the coming weeks. Meanwhile, France will back Bolivia's efforts for financial aid in international organizations and urge other European countries to help the government, French officials say.

While Bolivian leaders say that political and financial support is welcome, the internal political effect of the expulsion may not be as beneficial.

"Who in Bolivia is going to worry about somebody like Klaus Barbie at a time like this?" said a leading senator in the government's party. "There are a million other problems that people are thinking about."