No idea whether it is true or not, as it comes from Asahi Shinbun's "Asia and Japan Watch" (AJW) which has had very inaccurate headlines and articles regarding the nuclear accident.
From AJW, article by Kamome Fujimori (part; 5/12/2012):
Unease abroad over the post-3/11 situation in Tokyo is hardly new, however. Sports officials have had to deal with the reassignment of several events scheduled for Japan and some cancellations after the nuclear disaster.
One example was the 2011 World Figure Skating Championships, originally scheduled to be held in Tokyo in late March, but later reassigned to Moscow. The 2011 World Gymnastics Championships in Tokyo in October also appeared to be in danger at one point, but the Japan Gymnastic Association waged a successful campaign to reassure officials in other countries that Tokyo was safe enough to host the event as scheduled. It should be noted, however, that when some members visited Germany as part of that campaign, they were not allowed to get on a bus on the grounds that “people from Tokyo are contaminated.”
Ironic that Germany did that, if this Asahi's article is correct.