The founder of India’s biggest coffee chain has gone missing after allegedly writing a letter that apologizes for his failures and accuses tax officers of harassment.

V.G. Siddhartha, chairman and managing director of Coffee Day Enterprises, has not been “reachable” since Monday evening, the company said in a news release. The Bengaluru-based business is the parent company of the Café Coffee Day chain.

“We are shocked by this development and our thoughts and prayers are in support of his family and loved ones,” the release said, adding that the board is “formulating appropriate steps to ensure business operations are unaffected, and has resolved to cooperate with authorities.”

People walk outside a branch of Café Coffee Day, India's largest cafe chain, in New Delhi. (Rajat Gupta/EPA-EFE/Shutterstock)

The company’s news release included a letter that it said was “purportedly” signed by 59-year-old Siddhartha. The letter, dated July 27, said he had “failed as an entrepreneur,” referencing Coffee Day’s internal financial struggles.

“I gave up as I could not take any more pressure from one of the private equity partners forcing me to buy back shares,” the letter said. “I would like to say I gave it my all. I am very sorry to let down all the people that put their trust in me. I fought for a long time but today I gave up as I could not take any more pressure from one of the private equity partners forcing me to buy back shares.”

It also refers to the strain he said he faced from an unnamed tax official. The Income Tax Department said in a release that the note’s authenticity is “not known” and “does not tally” with Siddhartha’s signature in his annual reports.

Local police say Siddhartha was last seen on a bridge over the Netravati River near Mangaluru in the south Indian state of Karnataka. Rescue teams, divers and sniffer dogs have been deployed for the search operation.

Coffee Day was founded in 1993 and now has at least 1,750 outlets in more than 245 Indian cities. It also has a presence in Egypt, Malaysia and Nepal. The chain reported revenue of more than $263 million for fiscal 2019, according to Business Standard.

The board held an emergency meeting Tuesday evening, local time, according to Live Mint. Coffee Day shares on the Mumbai Stock Exchange dropped 20 percent soon after the release.

Several people responded with concern on social media after the news was released.

“Shocked by VG Siddhartha’s sudden disappearance. Hope he is safe & found soon,” Milind Deora, a politician from India’s financial capital, Mumbai, said in a Twitter post. Calling him “an exceptional entrepreneur who introduced millions of Indians to coffee, Deora said, “His is the ugliest example of how agency persecution is wrecking India’s growth story.”

Niha Masih reported from New Delhi.