In Do Travel Writers Go To Hell?, Mr Kohnstamm, 32, discloses that there was nothing lonely about his three years travelling through Latin America, working on a dozen different titles.
"The waitress suggests that I come back after she closes down the restaurant, around midnight," he writes. "We end up having sex in a chair and then on one of the tables in the back corner.
" That performance earned a guidebook entry describing the restaurant as "a pleasant surprise" where "the table service is friendly". He also recounts how he shared his apartment with a Brazilian prostitute called Inara. Short of cash, he admitted selling ecstasy to pay his way.
Lonely Planet bosses are not amused. Last week, the company's chief executive, Judy Slatyer, sent an email to her writers condemning Mr Kohnstamm. Her greatest concern is his assertion that his advance payment was "barely enough to cover the air fare" and that many guide book writers do not check their facts in a bid to finish before they "run up credit card debt" and "burn out".