Many of the recipients said they were disturbed and frightened

An Indonesian marketing executive who anonymously sent coffins to journalists and celebrities to promote a new book is being investigated for “unpleasant acts”, police said Tuesday.

Sumardy Ma sent dozens of small coffins to newsrooms, advertising and social media personalities on Monday with anonymous messages pointing to a website promoting his book on word-of-mouth marketing.

Many of the recipients said they were disturbed and frightened, and some threatened to sue.

Former journalist and prominent blogger Ong Hock Chuan, who received one of the coffins, condemned the stunt as “an insensitive, stupid and cheap stab at publicity”.

“There is creativity and then there is creative stupidity. If you don't worry about the consequences you could always get lots of cheap publicity,” he wrote in his website, theunspunblog.

Police officer Johanson Simamora said Ma could face up to a year in jail.

“We have named Sumardy a suspect due to his unpleasant act,” he said.

Ma has told reporters the coffins were designed to create a buzz around his product.