Muster, the world No 3, claimed spectators threw things and spat at players after walking off during his doubles match on Saturday. Members of the Austrian team also alleged that they had heard death threats from the crowd.
Muster's angry exit with Austria 0-2 down in the final set of the doubles handed Brazil a 2-1 lead. When his Austrian team-mates refused to play yesterday's reverse singles, officials gave Brazil a 4-1 victory and a place in next season's World Group.
"It was absolutely impossible for me to go out on court again," Muster said. "For three and a half hours, we were sworn at, had things hurled at us, spat upon. I want police protection and will never again play here. This country should finally be punished. If this is Davis Cup, I don't want anything more to do with it. The people here are like animals."
The Brazilian team captain, Paulo Cleto, said: "This is certainly the most stupid excuse I have ever heard. Nobody is shot because of tennis."
The International Tennis Federation will investigate, but they are not on Muster's side. "In the opinion of the referee Muster's complaints were not justifiable," the ITF said.
Thomas Enqvist clinched Sweden, six times champions, a place in November's final against either France or Italy when he fought back from two sets to one down to beat the Czech Daniel Vacek in Prague.
Enqvist, Sweden's No 1, took the first reverse singles match 6-3, 6-7, 4-6, 7-5, 6-3 to give Sweden an unbeatable 3-1 lead in their World Group semi-final.
In other World Group qualifying matches, Romania came beat Belgium 3- 2 in Bucharest and qualify for the first time in 12 years. The Netherlands overpowered New Zealand 4-1 in Haarlem to also go through.Reuse content