The founder of a startup acquired by Amazon for a reported $26 million is now investing in AI

A Cambridge entrepreneur who sold his company to Amazon is increasing the amount of angel investing he's doing now he no longer works for the e-commerce giant.

William Tunstall-Pedoe sold Evi Technologies, his voice recognition startup to Amazon in 2012, for an undisclosed amount that TechCrunch reported to be around $26 million (£20 million).

Following the acquisition, Tunstall-Pedoe became part of the Amazon family. However, his investment activities have been somewhat limited over the last four years.

"I did a bit of investment while I was in Amazon but obviously that was constrained by Amazon legal; I had to get permission if it overlapped at all with anything Amazon did and most things overlap with something that Amazon is doing," Tunstall-Pedoe told Business Insider at his home in Cambridge.

"Since February I've been much more active," he added, saying he's backed a total of 13 companies, including Magic Pony Technologies, which was acquired by Twitter in June for $150 million (£113 million), and mental health startup Big Health.

The Cambridge computer science graduate, who is currently on a career break, states on investor website Angel List that he's "primarily interested in advancing the state-of-the-art of what computers can do in a way that has an enormous positive impact globally."

Tunstall-Pedoe, whose IP sits at the heart of AI assistant Amazon Alexa and the hardware that supports it, Amazon Echo, has also become a fellow at a startup incubator in Canada called the Creative Destruction Lab, where he "might be" making some personal investments.

"They have a very big machine learning track," he said. "I'm basically going to go to Toronto every couple of months for the next year, immersing myself in many 10s of AI machine learning startups.

"They've got this very very capitalist mission which is to maximise the equity value of the companies that pass through them. They're trying to create hundreds of millions worth of dollars of value but they themselves are non-profit."

When asked about UK incubators, Tunstall-Pedoe said he's interested in London-based startup factory Entrepreneur First but that he keeps missing their demo days.

Tunstall-Pedoe said he's gently thinking about what to do next in his career, adding that it's quite likely to be another AI startup.