Intel chief executive Brian Krzanich has resigned after an investigation revealed a past relationship with another employee violated the microchip giant's company policy.

The US company said: "An ongoing investigation by internal and external counsel has confirmed a violation of Intel's non-fraternization policy, which applies to all managers."

Mr Krzanich was a veteran executive of the company, joining the company in 1982 and serving as chief executive since 2013. The consensual relationship was said to be "some time back", according to CNBC.

Intel has named Robert Swan, the company's chief financial officer, as interim chief executive.

Mr Krzanich was one of the highest paid chief executives in the US, taking home a pay package of more than $21m.

He was criticised in November last year for selling $39m in shares shortly before Intel admitted to a security vulnerability in its microchips that had been used in computer processors in millions of devices.

The Intel boss promised a fix for the devices during a speech in January. The company has been hit by lawsuits since following the revelations.

Last year, Mr Krzanich joined calls from other US tech leaders for protection for children of immigrant workers in the US, known as dreamers.

Intel said it had started the process for searching for a new chief executive officer.