Police said Mr. Lenz, author of the 1995 novel Surfing the Himalayas, may have died Monday from a drug overdose or accidental drowning. An autopsy was pending.
A pier railing at his estate was bent or broken. Divers found his body in 20 feet of water in Conscience Bay, about 60 feet from land. "It appears he fell into the water from a floating pier, but the circumstances leading up to that are still unclear," Suffolk County Detective Lt. John Gierasch said.
Mr. Lenz, who for a time called himself Zen Master Rama, recruited spiritual followers starting about 1980. But he told the Washington Post two years ago that his primary business had become software development and computer seminars, for which students paid $3,500.
Former followers called him a con man who encouraged them to sever family ties and used them for sex and to enrich himself. Mr. Lenz denied this, but said sex with students was "perfectly acceptable."
He maintained that his training had enabled followers to become millionaires. Lenz-Watch, a parents group, said he took in as much as $6 million a year from his students.
His followers reportedly never numbered more than a few hundred at any time.
Surfing the Himalayas, about a snowboarder who hooks up with an Eastern sage, was a best-seller in 1995. Mr. Lenz followed it up in 1996 with Snowboarding to Nirvana.
In 1995, New York magazine put him on its list of the "100 Smartest New Yorkers."
Mr. Lenz was born in San Diego in 1950, but grew up in Stamford, Conn. He received a doctorate in English from the State University at Stony Brook in 1978.
He became a recruiter for Sri Chinmoy, a New York-based teacher of a form of Hinduism and promoter of physical fitness. He struck out on his own in 1980 in San Diego.