Robert Smith, the founder of Vista Equity Partners, which counts Mindbody and LogicMonitor in its portfolio, is facing an investigation by U.S. tax authorities over his personal offshore holdings.

According to reports first published in Bloomberg, then in the Financial Times and others, Smith has come under scrutiny over tax treatment of millions of dollars in gains in his personal portfolio. In a letter to clients reviewed by the Financial Times, Vista Equity said it hoped Smith would resolve his dispute with the Department of Justice.

Smith made global headlines when he promised to pay off the college debts of graduates of Morehouse College, but he has been well known on the Central Coast for years. Among Vista’s portfolio companies are Santa Barbara-based Logic Monitor, a privately held cloud software company, and San Luis Obispo-based Mindbody, a formerly public software company acquired in a go-private transaction worth $1.9 billion.

Vista Equity has also has owned minority stakes in The Trade Desk, a Ventura advertising technology firm, and Sonos, a Santa Barbara audio hardware company. In recent years, Smith has vaulted past Oprah Winfrey, a part-time Santa Barbara resident, to claim the title of the wealthiest Black person in America, worth an estimated $9 billion.

The Financial Times, citing the client letter it had reviewed, said the tax dispute over accounting for gains earned offshore dates back to 2016.