German lighting designer Hess AG said it had sacked the two members that made up its management board after uncovering fraud that had been going on for a "remarkable period of time".
Hess, which floated in October, said it suspected that non-existent revenue and income had been declared, meaning its financial situation was described too positively.
"The company has probably been, with the knowledge of the management board, in continuous breach of accounting rules for a remarkable period of time," it said in a statement on Monday.
Its shares crashed 55 percent after the announcement to 6.70 euros ($8.91), compared with October's issue price of 15.50 euros.
It would be looking into taking legal action to recover damages, it said.
($1 = 0.7524 euros)
(Reporting by Victoria Bryan; Editing by Erica Billingham and Helen Massy-Beresford)