Intel CEO Brian Krzanich. AP

WASHINGTON - Intel CEO Brian Krzanich has resigned over an inappropriate relationship with an employee. 

The married 58-year-old stepped down on Thursday after an internal investigation by the tech company revealed what it described as a 'violation' of its 'non-fraternization policy'. 

Krzanich, who has been the CEO of Intel since 2013 and is married with two daughters, quit immediately. 

He is yet to comment on his departure or the nature of the relationship. 

It remains unclear who the employee was, how long it lasted and if they still work for the company. 

'Intel was recently informed that Mr. Krzanich had a past consensual relationship with an Intel employee.   

Bob Swan, the company's Chief Financial Officer, will serve as the interim CEO until a permanent replacement can be found. 

'The Board believes strongly in Intel's strategy and we are confident in Bob Swan's ability to lead the company as we conduct a robust search for our next CEO.

'Bob has been instrumental to the development and execution of Intel's strategy, and we know the company will continue to smoothly execute.

'We appreciate Brian's many contributions to Intel,' Chairman Andy Bryant said.

Krzanich's oldest daughter is in college and his youngest is still in high school.  The family lives in Camino, California, around 140 miles from San Francisco.

Intel's share price dropped by almost 1 percent during early trading as the news emerged. 

It opened at $54.39, its highest of the week, but dropped to $53.28 within the first 30 minutes. 

According to The New York Times, Krzanich earned a $21 million as Intel's CEO.