But talks between Berlin and Moscow have since prompted a change of heart from the World Cup hosts and Seppelt will now be allowed to enter Russia after government officials "made an exception to the rule".
"His exclusion was stipulated specifically for the FIFA World Cup." FIFA, football's world ruling body, used the occasion to stress the importance of media freedoms to President Vladimir Putin's government.
"We regret the inconvenience experienced by the journalist," FIFA said in a statement released to AFP.
"As stated on many occasions and in line with FIFA's Human Rights Policy, press freedom is of paramount importance to FIFA." Seppelt, though, may think twice about booking his ticket for the June 14-July 15 showpiece.
Russia's powerful Investigative Committee said it intended to question him on his arrival because he was a key witness in its own investigation into the scandal.
Seppelt's TV reports concluded that Russia's doping programme was being overseen by the state's security service, and that orders for athletes to cheat on a such a scale could only have come from Putin himself -- charges which have been vehemently denied by Russia.
The visa denial created a furore in Berlin.
"I told him that I hoped he would personally get in touch with the Russian government," Grindel said.
- 'Unwanted visitor' -
Moscow's German embassy spokesman Denis Mikerin confirmed to Russian state media that Seppelt was denied a visa last week.
"Nevertheless, in case Hajo Seppelt appears in Russia, the Investigative Committee once again will take steps to question him about things he learned while preparing a documentary about supposed wrong-doing by Russian athletes."
Russian investigators said Seppelt was a prime witness in its probe into Russian doping whistle-blower Grigory Rodchenkov.
The former Moscow lab director is living in hiding in the United States after revealing details about Russia's alleged doping violation to Seppelt. Rodchenkov is suspected by Russia of abusing power and destroying doping samples at the lab.
Moscow officials claim that Rodchenkov fabricated the entire doping story from the start.