Problems at the Ofex-quoted business also prompted the resignation yesterday morning of Tom Mackay, Display IT's company secretary and a partner with the solicitors Taylor Johnson Garrett. The law firm has also resigned as the company's solicitors.
The law firm said Mr Mackay had resigned "following his inability to obtain certain information from the company about its affairs".
It is understood this information relates to Display IT's relationship with Alsina, a Luxembourg-registered company, which has a contract to distribute Display IT's services throughout Europe. Display IT has consistently refused to say who is backing Alsina.
Earlier this week Bill Murphy, BT's director of corporate clients, also resigned from the Display IT board.
Display IT was unavailable for comment yesterday.
Recent volatile movements in the company's shares have prompted the Securities and Futures Authority to look into the matter in its capacity as regulator of Ofex's only market-maker, JP Jenkins.
Display IT's shares were suspended at 245p. Last Friday they fell 75p to 145p, 48 hours after Display IT's original firm of PR advisers, College Hill, had resigned from the account. The shares stood at 810p earlier this year. Alex Sandberg, College Hill's owner, said last week that his firm had resigned because the company had refused to reveal who owned Alsina.