San Francisco police say that they responded to a report of a stabbing in the early hours of Tuesday and found a 43-year-old man with wounds. He later died in hospital.

Lee’s father, Rick Lee, confirmed the news in a Facebook post: "I just lost my best friend, my son Bob Lee when he lost his life on the street in San Francisco early Tuesday morning."

Lee spent six years at Google before joining Square, now Block, in 2010, creating the hugely popular Cash App and serving as CTO.

Most recently he had been chief product officer at cryptocurrency firm MobileCoin.

On social media platform Nostr, Block boss Jack Dorsey called the death "heartbreaking," adding that “Bob was instrumental to Square and Cash App”.