Mr Young was fired in September 1996, following the discovery of "serious rregularities" in three of his funds.
The four former directors have had their Imro registrations suspended for periods ranging from 16 months to three years and have been ordered to pay Imro's costs.
Elements of the investigation process have caused unease in some areas of the City. In particular, there has been concern that high legal costs could have deterred the four from taking their cases to an independent tribunal.
Graham Kane, formerly managing director of Morgan Grenfell Unit Trust Managers (MGUTM), has had his Imro registration suspended for 16 months, and will pay Imro's investigation costs of pounds 90,740 as well "as a contribution to its disciplinary costs".
Paul Ebling, formerly a compliance officer at Morgan Grenfell, has had his registration suspended for two years and has undertaken not to apply for a senior compliance position for a further 12 months. He will pay Imro's investigation costs of pounds 69,450 and a contribution towards its disciplinary costs.
Glyn Owen, formerly chief executive of Morgan Grenfell International Fund Management (MGIFM), has had his registration suspended for three years, and will pay Imro investigation costs of pounds 88,770. He too will pay a contribution to Imro's disciplinary costs.
The most severe penalty was reserved for Michael Wheatley, formerly a Morgan Grenfell compliance director. He has had his Imro registration suspended for three years, has been permanently restricted from holding a compliance position, has been ordered to pay Imro's investigation costs of pounds 90,850 and a contribution to its disciplinary costs. Mr Wheatley has left the City to pursue a career in academia.
The suspensions are back-dated to 4 December 1997, when Imro's enforcement committee first met to discuss penalties.
Keith Percy, formerly chief executive of Morgan Grenfell Asset Management, is understood to be in settlement negotiations with Imro. Mr Percy, who has substantial personal wealth, is believed to be considering taking his case to an independent tribunal.
Concerns over legal costs are believed to have deterred the four other directors from taking the tribunal route. According to some City estimates, an individual who decides to take their case to tribunal could incur costs of more than pounds 250,000. And if the individual loses, he or she then becomes liable for Imro's costs, which could exceed pounds 500,000.
While most in the City agree with the principle of the accountability of senior management, concern has been expressed in some quarters over the manner in which Imro conducted its investigations.
Philip Warland, director general of the Association of Unit Trusts and Investment Funds, is just one leading City figure with doubts about the disciplinary process.
Mr Warland, one of the few in the City prepared to air his views publicly, said: "I have no difficulty with the situation that when companies take the public's money, they should be held accountable. Similarly, senior management should be held accountable."
However, Mr Warland said he was concerned about the time and the costs of the process. He was particularly worried that individuals were being "effectively denied access to tribunal". "At the tribunal, the prosecutors' costs are borne by the accused if they lose. . . That doesn't happen if you're a murderer."
Mr Warland added he would be campaigning to ensure Imro's enforcement procedures would not be adopted when procedures were harmonised across the FSA, the new industry-wide regulator.