This would come as a severe blow to Morgan Grenfell, which has been battling to rebuild morale, and retain clients, after the Peter Young affair, which had already cost the jobs of some of the most highly respected names at the group, including Keith Percy, chief executive of Morgan Grenfell Asset Management.
Geoff Henry, chief executive of the Merchant Navy Officers' Pension Fund, which has around pounds 50m invested with MGAM, said the trustees of his fund were concerned about the management structure of the group when the antics of Peter Young were uncovered.
"What we're seeing now [with the suspension of Mrs Horlick] is a vital element being removed from the situation. That is a destabilisation," said Mr Henry. The trustees' previous concern had not been about the investment track record, but more about the internal management of the operation.
However, Morgan Grenfell was understood to be confident that it would not lose business as a result of the affair.
Mrs Horlick was suspended after Deutsche Morgan Grenfell suspected that she had attempted to lure as many as 20 colleagues from the fund management group to join a rival investment management firm.
But the move appears to have backfired after she approached potential candidates before signing a conclusive deal with ABN Amro, the Dutch banking group with which she was widely believed to be in negotiation.
"We never comment on who we are talking to before anything is concluded," a spokesman for ABM Amro in Amsterdam said yesterday.
But he added: "We are surprised to be mentioned in the context of poaching, which would, by its nature, imply you are planning to take a whole team, which we are not.
"When it comes down to talking to individual people, you are not talking about poaching."
Morgan Grenfell insiders suggested yesterday that Mrs Horlick, like others in the City, had been known to make noises about tendering her resignation around this time of year. This is because bonuses are paid late next month and a resignation threat encourages employers to beef up bonus payments and remuneration deals.
It emerged yesterday that Mrs Horlick's investment banker husband, Tim, who works at Salomon Brothers, is fighting a legal action by his previous employer, Dresdner Kleinwort Benson.
"An injunction was taken out at the end of July and we are still continuing the legal proceedings until an acceptable final settlement has been reached," a spokesman for Kleinwort said.
Both Salomon Brothers, which is not cited in the injunction, and Mr Horlick declined to comment.
The precise details of Mrs Horlick's pay deal remain a mystery although sources said that in a good year her total package could easily top pounds 1m.
She is managing director of Morgan Grenfell Investment Management, one of the bank's fund management arms. A search at Companies House showed the highest-paid director at MGIM in 1995 earned pounds 248,000. That is likely to exclude any bonus payments.
Leaving her plush, four-storey stucco house off Kensington High Street in west London yesterday morning, she told waiting photographers she was "going into the office". But her whereabouts remained a mystery throughout the day.
Tabloid, pages 2 and 3
Comment, page 21