Police sources say Alexei Navalny was under surveillance in Siberia

Leak to newspaper is apparently intended to show Navalny was not poisoned in city of Tomsk

A Russian newspaper has alleged there was extensive government surveillance of the Kremlin critic Alexei Navalny during a trip to Siberia before he collapsed from a suspected poisoning on Thursday.

Navalny's press secretary, Kira Yarmysh, had complained of being followed during the trip, calling the police surveillance absolutely obvious" during a stopover in the city of Novosibirsk. The next leg in the city of Tomsk was relatively calm", she said, until Navalny fell ill during a return flight to Moscow on Thursday. He was transferred to Berlin's Charite hospital on Saturday for treatment.