The U.S. Securities and Exchange Commission is investigating the Japanese internet and telecommunications giant SoftBank Group Corp., and its former executive Nikesh Arora, according to a lawyer for disgruntled investors in the company.

"We do know that the SEC…is inquiring into certain matters concerning SoftBank and Mr. Arora," the lawyer, Ira Sorkin, said.

Mr. Arora abruptly left the company last week, two years after he was wooed from Google Inc. and had emerged as the heir apparent at the firm. He had been SoftBank Group's president and chief operating officer.

SoftBank CEO Masayoshi Son, who had handpicked the Silicon Valley deal maker to be his successor, last week attributed the departure to his decision to extend his stay at the helm of the company he founded.

Mr. Arora's departure also came after he faced a barrage of criticism from investors over lackluster investments, with some shareholders mounting a campaign to oust him. They questioned his record and suggested his role as an adviser to private-equity firm Silver Lake constituted a conflict of interest.

In a statement, the company said it doesn't comment on press reports of regulatory inquiries. It said a committee of its board reviewed the shareholder allegations and concluded they were without merit.

Mr. Arora, whose $208 million compensation from SoftBank over the past two years made him one of the highest-paid executives in the world, has said the investors' claims were groundless.

A SEC spokeswoman declined to comment.

The investigation was reported earlier by Bloomberg News.

Write to Aruna Viswanatha at Aruna.Viswanatha@wsj.com

(END) Dow Jones Newswires

July 01, 2016 13:25 ET (17:25 GMT)