"We do not know where Spiegel received this information from. We do not comment on security measures, this is our principle," the spokesman said.
Earlier in the day, the magazine reported that the police had boosted security in the Charite hospital, where Navalny is being treated after the alleged nerve agent poisoning, "out of fear of a new attack".
According to the German newspaper, the measures were taken as Navalny's condition continues to improve: he has supposedly gained the ability to speak and remembers what happened on the Moscow-bound flight before he fell ill on 20 August.
Earlier this week, Zeit newspaper reported that Germany believes Russian opposition figure Alexei Navalny survived only thanks to the pilot who made an emergency landing in the Russian city of Omsk and the efforts of local doctors.
In early September, German authorities claimed that an analysis of samples of Navalny’s biological material showed that he was poisoned by a nerve agent of the so-called ‘Novichok’ group, and his case this would be treated as “attempted murder by poisoning.”
Moscow asked Berlin to provide evidence to back up its claims.
"We expect Berlin to provide all the available data: both the results of the Bundeswehr's laboratory tests and the 'evidence' that the German Foreign Ministry has... It is time to show the cards since everyone understands that Berlin is bluffing, as it serves the interests of some dirty political bustle," Russian Foreign Ministry spokeswoman Maria Zakharova said.
On 20 August, Navalny fell gravely ill during a domestic Russian flight. Following an emergency landing in the Siberian city of Omsk, he was taken to a local hospital and, according to regional doctors, he arrived just 17 minutes after landing.
For the next 44 hours, doctors waged an uninterrupted struggle for his life, as he went into a coma and was put on an artificial lung ventilator.
Upon conducting multiple tests, Russian medics established that no traces of poison had been found in his system, saying that Navalny's condition was caused by an abrupt drop of glucose in his blood due to a metabolic imbalance.
On 22 August, Navalny was flown to Berlin for further treatment. German doctors claimed that they had found traces of a substance from the group of cholinesterase inhibitors in his body, which the Russian doctors denied, referring to his test results.