SoftBank Corp. says it is investigating a shareholder campaign that sought the ouster of former Google executive Nikesh Arora, who had been groomed to lead the Japanese technology company. Arora, who joined SoftBank as president from Google in 2014, had been expected to succeed Son as head of the company. But in 2016, SoftBank founder and Chief Executive Masayoshi Son said Arora was leaving. Son remained at the helm. The Wall Street Journal reported this week that some shareholders had conducted a smear campaign to discredit and oust Arora. SoftBank confirmed Wednesday a committee of its board of directors was investigating but declined further comment. Earlier, SoftBank said an investigation into allegations against Arora that were raised in letters from a law firm claiming to represent shareholders found no wrongdoing.