Rights groups have accused Kadyrov of trying to eliminate opponents
Chechnya's leader had "nothing to do" with a dissident's murder in Austria, his spokesman said, after police there linked Ramzan Kadyrov to the killing.
Spokesman Alvi Karimov said this was a clear attempt to smear Mr Kadyrov.
Austrian police concluded Mr Kadyrov ordered Umar Israilov's abduction but he was killed when it went awry. Three Chechens are being held in the case.
Rights groups have long accused Mr Kadyrov of a campaign to eliminate opponents at home and abroad.
Although three Chechens are being held in Austria over last year's killing - Otto Kaltenbrunner, Muslim Dadayev and a third, unnamed suspect - no charges have yet been brought.
Austrian counterterrorism investigators have completed a 15-month inquiry and have submitted their report to the Vienna public prosecutor's office, which will decide on charges.
But a spokesman for the office, Gerhard Jarosch, said it was assumed "that Kadyrov is behind the murder of Israilov", a former bodyguard of the president, and that he ordered his abduction.
The BBC's Rupert Wingfield Hayes in Moscow says the evidence linking Ramzan Kadyrov to the murder is far from conclusive and Austrian prosecutors have admitted as much.
But the prosecutors say the evidence does show that the three men suspected of carrying out the killing had close ties to the Chechen leader and his henchmen.
They have a photograph of one of the suspects sitting on a sofa next to the Chechen leader.
They also know that one of Mr Kadyrov's closest advisers visited Austria two months before the killing and that he was met at the airport by one of the men now in custody.
And police found a copy of that same senior adviser's passport inside the alleged getaway car.
But Mr Karimov dismissed the allegations.
He told the BBC: "What we're seeing here is a very clear desire to smear the name of the Chechen president. Mr Kadyrov had nothing to do with this killing. The man who was killed was completely irrelevant - he had no influence on what's going on in Chechnya.
"Moreover, when he said he wanted to return to Chechnya, Kadyrov made a statement saying that man was welcome in the republic."
Mr Karimov said if Mr Israilov had returned then "certain people" would not have been able to use him as as symbol anymore.
"Who are these people? It's hard to tell. It's the people who lost the war. Who lost to Ramzan and to Russia in an open battle. So now they are doing this. We know 51 countries were involved in fighting Russia and Ramzan in Chechnya."
Mr Israilov, 27, was shot on 13 January 2009 outside a grocery store in Vienna.
He said he had witnessed President Kadyrov personally taking part in torture sessions.
Russia fought Chechen rebels in two conflicts in the 1990s and then persuaded the Kadyrov clan to switch sides and administer local government, reducing the violence there.