Former Brewin Dolphin head of split caps David Thomas, the investment trust designer said to have developed the modern split-cap structure, is believed to have been refused authorisation by the FSA.
Thomas is understood to have appealed against the decision to the Financial Services and Markets Tribunal, the statutory body for individuals' and companies' complaints about FSA regulation.
Thomas had been planning a return to the financial industry after leaving Brewin Dolphin in January after the firm was widely criticised for its split-cap role.
Thomas helped to create a number of split-capital investment trusts in the late 1990s and is understood to have been paid more than £3m in salary and bonuses between 1999 and 2001. He was responsible for designing Aberdeen Asset Management's preferred income trust.
In October 2002, he admitted to the Treasury select committee that his firm had given the wrong advice to clients because it relied on information in split-cap prospectuses.
He has denied all knowledge of a “magic circle” in the split-cap sector.