"We want to continue to work with non-disabled and disabled athletes, but we must ensure there is a level playing field," said Clemens Prokop, the president of the German Athletics Association (DLV).
The DLV took biomechanical measurements of Rehm and his rivals during the German championships in Ulm last weekend. The results led to concerns that the 2012 Paralympics champion may have benefited from his prosthesis.
"The values measured in Ulm show that sprint and take off are significantly different," said Prokop.
'Doubt over leg'
The 25-year-old Rehm, whose right lower leg was amputated after a wakeboarding accident, won the national long jump championships with 8.24 metres.
The measurements, taken by sport scientists based at the Olympic training centre in Frankfurt am Main, found significant differences between Rehm and Christian Reif, who finished second in Ulm.
Rehm had a slower sprint but an "above average vertical velocity when leaving the ground," which may be the result of a catapult effect of his prosthesis' carbon spring.
"There is a strong doubt that jumps with a leg prosthesis and a natural ankle joint are comparable," said Prokop.
Head coach Idriss Gonschinska said the DLV did not make its decision lightly. "In this situation, we had to weigh everything really very carefully and had a lot to weigh," he said.
Rehm initially said he would accept the DLV's decision regardless of the outcome but did not rule out legal action after the decision was announced on Wednesday.
"It's a shame and I'm disappointed," he said after the ruling.
'More to do'
Over the last few days, experts criticized the DLV for mismanaging the case.
"It cannot be a data-based and credible assessment," said Gert-Peter Brüggemann, a biomechanist at the German Sport University in Cologne. "What can be done during a competition is absolutely not enough to say whether and how a prosthesis works compared to healthy, capable joints."
"One has to do more than video recordings and some speed measuring," Brüggemann added.
The DLV said it will seek clear rules for the participation of athletes with disabilities when the International Association of Athletics Federations (IAAF) meets next year.
Germany will now be represented by current European champion Christian Reif and Sebastian Bayer, a former European champion. Bayer, who came fifth in Ulm, said after the competition that he suspected Rehm could have had an advantage thanks to his leg prosthesis.
The third German long jumper will be Julian Howard, whose 8.04-metre jump in Ulm did not automatically qualify him for Zurich but still made him eligible to be nominated.