Barnaby Jack, a security expert hacker, has passed away at the age of 35 in San Francisco but the conditions surrounding his death are not known.

Jack was expected to present his findings into the security vulnerabilities of implanted medical devices. His research has forced many pharmaceutical companies to rethink their devices as it was proven that hackers could easily cause harm to the people. He has exposed security flaw in insulin pumps forcing the firms to review security on the devices.

The San Francisco medical examiner's office only said that Jack died in the city on Thursday without giving any further information. Jack had earned respect in the information security world for himself and was a popular and respected figure due to his pioneering research work. Jack was set to give a presentation into medical device vulnerabilities at the Black Hat security conference in Las Vegas next week.

Mr Jack has been working as the director of embedded devices security firm IOActive. The company said in a tweet that, "Lost but never forgotten our beloved pirate, Barnaby Jack has passed."

The company said that it is preparing a statement.