Bruno Manser has always had a streak of daring. Last year the Swiss environmentalist descended by motorized paraglider into the remote Malaysia state of Sarawak. He wanted to deliver a symbolic toy lamb to Sarawak Chief Minister Taib Mahmud during a Muslim holiday. The minister was not amused and quickly deported the activist. Manser had already been banned from the country for his efforts to protect the Penans, who are one of the world’s few remaining nomadic rain-forest tribes. Manser, 45, believed the tribe was under threat from logging companies. He lived in the jungle with the tribespeople for six years, from 1984 to 1990. Over the past 15 years, through various publicity stunts and protests, he called attention to the clear-cutting of Borneo’s lush forest, and to the plight of the Penans. He also confounded Malaysian authorities and enraged local timber interests.

Now he is missing in the Borneo jungle. Last May 22 Manser sneaked into Sarawak, slipping across the border via the neighboring Indonesian province of Kalimantan. He returned, according to the Swiss-based Bruno Manser Fund, to visit his old tribal friends who “are under greater threat than ever before.” But Manser hasn’t been seen since. His family is worried that he got lost, hurt or ambushed while trekking through the jungle by himself. King cobras and pythons are a natural threat in the bush. Some friends suggest that he may have been killed by gangsters working for logging companies. There have been four searches by the Penans themselves, but they’ve turned up nothing. Three weeks ago the Manser family asked the Malaysian government for help locating the activist. Nothing much has been done–though when queried by a local newspaper about Manser’s disappearance, a Sarawak politician sent the missing Swiss activist a terse message: “We don’t want you here,” said Sen. Joseph Balan Seling to the missing Swiss man. “Don’t get in touch with the Penans. Don’t influence or disrupt their lives again.”

Manser first took up the Penan cause in 1984. Soon after, the previously docile tribesmen began throwing up blockades to obstruct the logging industry–the state’s biggest industry. Hundreds began to camp out at lumber sites, demanding government recognition of native lands, and fair compensation. No one disputes the fact that widespread logging has disturbed the lifestyle of the 10,000 Penans in Sarawak. Most now live in villages, but a few hundred still live a primitive existence in the Borneo rain forest. They eat sago (a paste derived from palm trees), along with meat from bear, deer and wild boar. As timber companies slice farther into the Borneo interior, environmentalists say the logging destroys sago palm trees, pollutes rivers and scares off game.

Government officials, many of whom own sizable stakes in the local timber companies, are not sympathetic. Malaysia has long been one of the world’s largest exporters of tropical timber, and has experienced one of the fastest rates of deforestation in the world. Through his relatives, Taib is alleged to be a major player in the industry. He drives a vintage Rolls-Royce.

Manser’s sustained environmental campaign has certainly cut into logging profits. But Sarawak officials insist that their main complaint is that Manser’s efforts have only slowed the Penans’ transition into normal society, where they can receive education and better health care. “How can we have an equal society when you allow a small group of people to behave like animals in the jungle?” argues Taib. “I owe it to the Penans to get them gradually into the mainstream so that they can be like any other Sarawakian.”

Some of Manser’s friends fear he has met a violent death. For years there have been rumors of a $50,000 bounty on the activist’s head. “I wouldn’t put it past timber-company gangsters to disappear Bruno,” says Peter Brosius, an anthropologist and Penan authority at the University of Georgia. Once inside Sarawak, say Penan sources, Manser trekked around, meeting several small bands of tribesmen. It was during a three-day trek from one nomadic group to another that he disappeared. That may have been a mistake. Even Penans rarely travel for that long alone. Some are holding out hope that Manser has got another trick up his sleeve. James Ritchie, a Kuching-based reporter who’s written a book about Manser, believes the environmentalist is alive and planning a new publicity stunt. And if not? “If Bruno is dead, there is no Penan cause,” says Ritchie. “No one else is crazy enough to risk his life in the jungle, keeping attention on the issue.” For the time being, Manser is the issue. The Penans are still searching for him.