2018 Soccer World Cup (Supplied)
World Cup host Russia had initially refused to issue Seppelt a visa, but later relented after massive international pressure, with FIFA stressing the importance of media freedom to President Vladimir Putin's government.
But Germany's security agencies have since evaluated the situation and found that it was risky for the journalist to travel to Russia, said ARD in a statement late Wednesday.
Representatives from the broadcaster also held talks with Foreign Minister Heiko Maas over the security issue and the ministry shared the intelligence agencies' concerns.
Russia's powerful Investigative Committee has said it intended to question Seppelt on his arrival because he was a key witness in its own investigation into the doping scandal.
Seppelt's documentaries on doping among Russian athletes sparked a storm and ended up with Russia being banned from the 2018 Winter Olympics.
His 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.