Aegis, the UK-based advertising group, has suspended the head of its central and eastern European and South African business, Aleksander Ruzicka, over allegations of embezzlement.

Mr Ruzicka, who has been with the group's Carat agency for more than 20 years, is being investigated by the state prosecutor in Wiesbaden, which has raided homes and offices in several German cities, including Munich.

Two other Aegis managers, named in the German press as Claudia Condé-Jackson and David Linn, are said to be among nine others under suspicion but have not been formally notified of any investigation or charged.

Aegis said yesterday that it was working with the state prosecutor and had set up its own internal inquiry. "The prosecutor has confirmed that Aegis Media is not under investigation or suspicion so the investigation is into Alex personally."

The group, which is being stalked by its biggest shareholder, Vincent Bolloré - the French industrialist who is also chairman of the rival agency Havas - has temporarily promoted Andreas Bölte, the region's chief financial officer, as chief executive officer and says it has won the continued backing of global clients.

Mr Ruzicka's lawyer, Marcus Traut, has told German newspapers that his client rejected all the allegations. These are understood to centre on business with the Bonn-based firm Emerson Communications, which handles barter deals. The lawyer accuses unnamed rivals of planting these allegations.

German reports suggest that the allegations, which include tax evasion, are also concerned with widespread rebates used in the fiercely competitive media-buying market for television stations.

Earlier this month Aegis announced a 27% jump in net profits in the first-half to £33.2m on sales up 19% to £463.2m. Aegis's media buying and marketing business, Aegis Media, which includes Carat, made almost a fifth of its £280m half-year revenues from digital marketing.

In May Aegis fought off an attempt by Mr Bolloré to put two hand-picked directors on its board. Mr Bolloré, who owns 29.1% of Aegis, is now said to be ready to launch a second attempt to secure boardroom seats by calling for an extraordinary meeting of shareholders later this autumn. But the company said he had not requested an extraordinary general meeting, which could only be convened under strict procedures.