Ludger Beerbaum, seen here riding All Inclusive at the 2008 Olympic Games, has been suspended. ((Susan Walsh/Associated Press))

The German equestrian federation has disbanded its Olympic team and suspended a four-time Olympic champion after a string of allegations involving doping and the use of illegal medication on their horses.

The move on Thursday came one day after the country's two major television channels broke off talks with the equestrian body on a new broadcast contract, pending an investigation of the allegations.

The federation dissolved the show-jumping, dressage and three-day event teams and suspended top rider Ludger Beerbaum, a four-time Olympic champion who admitted last weekend to using illegal practices.

"We had to do something to wake them up," said Breido zu Rantzau, president of the federation known by its German initials, FN.

Olympic officials welcomed the decision.

"It's a radical move, with which the FN wants to conduct a comprehensive clearing up with the help of independent experts," said Michael Vesper, general director of the German Olympic Committee.

A three-member panel set up by the German Olympic Committee will conduct an investigation, starting in June, into the several positive tests for medication ahead of the Beijing Olympics last summer.

Christian Ahlmann was among several riders caught in Beijing for using forbidden substances on his horse and banned for six months. Such breaches of medication regulations are not considered doping and draw shorter sanctions.

The FN also said another horse may have been treated illegally in China, where German riders won three gold, one silver and one bronze medal.

Beerbaum, who was part of the Olympic show-jumping team, was suspended after admitting to illegal practices last weekend in a newspaper interview.

"In the past I had the attitude: anything that isn't found is allowed," he told the Frankfurter Allgemeine Sunday edition.