BEIJING — A trip to the sauna. A golf club membership. Luxury watches. Neatly packed bricks of red Chinese bills worth $220,000.

The bribes lined the pockets of health care officials across China. Their purpose: to get public hospitals to buy millions of dollars’ worth of sophisticated medical equipment made by foreign companies like General Electric, Siemens, Philips and Toshiba.

A review of dozens of Chinese court cases and internal corporate documents as well as interviews with company insiders showed how foreign firms have become deeply enmeshe d in the corruption pervading China’s health care industry. The New York Times reviewed more than a dozen cases in which employees of G.E., Philips and Siemens testified to bribing meagerly paid public hospital officials. In many other cases, Western companies signed off on deals involving third-party contractors who paid bribes and sought kickbacks. Sometimes, the companies continued to sign off on deals involving contractors who admitted to bribery in court .

In one case filed in 2016, a hospital administrator named Wu Dagong was offered more than a $1 million by two G.E. sales representatives to secure the sale of a CT scanner for $4 million. Mr. Wu also took a bribe — the $220,000 in bricks of bills packed in a suitcase — from a G.E. sales contractor, who walked with Mr. Wu to his car and left the suitcase in the trunk. Mr. Wu was sentenced to 15 years.