Staff at a New York clinic where Joan Rivers suffered a cardiac arrest have reportedly been bombarded with death threats.

The veteran funnywoman's heart stopped beating while she was undergoing a routine throat procedure at the Yorkville Endoscopy clinic in Manhattan on 28 August (14).

She was transferred to Mount Sinai Hospital but never recovered. Rivers died on Thursday (04Sep14), and bosses of the clinic have been swamped with nasty messages, according to Tmz.com.

Editors of the website report security has been stepped up at the facility.

Officials at the New York State Health Department have launched a review into the clinic.