It could be a story line worthy of “Law & Order,” the Indian version.

A technician reported last week that someone had tampered with a private helicopter of Anil Ambani, one of India’s wealthiest industrialists, while it was parked at a Mumbai airport. Then, on Tuesday, the technician, Bharat Borge, was found dead on railroad tracks in Mumbai. He was carrying a letter that mentioned the tampering investigation, Mr. Borge’s family and officials of Mr. Ambani’s company said.