"The situation" of Alexei Navalny "is critical, we are all very worried".
He told the Guardian Ruslan Shaveddinov, close to the Russian opponent in prison, who felt severe stomach pain on Friday night.
"We understood that the situation must have been very serious because an ambulance was called," he added, stating that prison authorities refused to admit Navalny to hospital.
The anti-Putin blogger's entourage believes he was poisoned:
"Our theory is that they are gradually killing him
, using a slow-acting poison through food," Shaveddinov said.
Shaveddinov said an ambulance was called last week
to the IK-6 maximum security penal colony
in Melekhovo, 250km from Moscow, where Navalny is being held.
And since then there have been no updates on his health conditions, because "the prison authorities are doing everything possible to isolate him", added the ally of the 46-year-old Russian opponent, who has to serve 11 years in prison for fraud and contempt to the court: allegations that according to human rights groups were fabricated to silence him.
As for the poisoning hypothesis, Shaveddinov recalled that
Navalny had already been a victim of novichok
, a Soviet-made nerve agent, during a trip to Siberia in 2020, for which treatment had been required in Germany.
"It might sound like paranoia, but after the novichok, it seems completely plausible. He's lost 8 kg in two weeks, this has never happened before and the doctors don't tell him why he's in so much pain," his ally added.
Concerns about Navalny's health have increased in recent months, so much so that earlier this year a group of Russian lawmakers and doctors defied the Kremlin by signing
a petition calling for adequate medical treatment
from the anti-Putin blogger.
Navalny's last social media post
dates back to Thursday, the day before his condition worsened.
On that occasion he had launched an appeal to the Georgian authorities to release former president Mikheil Saakashvili from prison and subject him to medical treatment.