An investigation by independent prosecutors was approved by the South Korean parliament last November and has up to 105 days to carry out its probe.
Samsung has denied the allegations and issued a detailed rebuttal of the lawyer's claims.
The company is South Korea's biggest conglomerate and the world's largest maker of computer memory chips and LCD display screens.
Samsung's assets have been valued at $280.8 billion while last year its exports were worth $66.3 billion, more than 20 per cent of South Korea's total.
Chu Woosik, Samsung's vice president, said the raids took place while he was holding an investor relations session at the group's headquarters on the company's latest financial results.
"It may be too much to say we are hit hard by this but it is true this affects us in a no-good way," he said.