Kremlin critic Alexei Navalny quipped that "everything is fine" and made jokes about prison life Wednesday as he sent his first message from a detention centre outside Moscow.

In the message posted on Instagram, President Vladimir Putin's most prominent critic said he was being held in the Kolchugino detention centre in the Vladimir region northeast of Moscow.

"But everything is fine with me, there's even a chin-up bar in the exercise yard here," he said.

Navalny was sentenced last month to two and a half years in a penal colony for breaching parole terms while in Germany recovering from a poisoning attack.

His message was posted after his defence team visited him in the Kolchugino jail, where he is under quarantine.

One of his lawyers, Olga Mikhailova, said he was expected to be held there until his sentence came into force and that he was in a good mood.

"He's feeling well," Mikhailova told AFP, adding that Navalny was sharing a cell with two people.

"The cell has nothing except a TV," she said, adding that he could not receive letters or buy anything in jail.

Mikhailova said it was not yet clear where Navalny would eventually be serving out his full sentence.

A Moscow official had earlier said it would be at a prison in the town of Pokrov in the Vladimir region called Penal Colony No. 2.

Eva Merkacheva, a member of Moscow's public commission that monitors detainees' human rights, citing sources, told AFP on Wednesday that Navalny was still expected to be transferred to the Penal Colony No. 2 in the future.

Navalny posted his message after his defence team visited him in the Kolchugino jail, where he is under quarantine
Navalny posted his message after his defence team visited him in the Kolchugino jail, where he is under quarantine AFP / Kirill KUDRYAVTSEV

In the light-hearted message, Navalny said he was not aware of what was happening in the world and has not yet managed to get any books from the jail library.

"That's why the only entertainment is haute cuisine experiments," he said, adding he and his cellmates were drying bread to make croutons.

"I never thought it could be so entertaining. Now we are having a competition of two cuisines: street food and molecular."

One of his cellmates, he said, was particularly happy to be sharing a cell with the opposition politician.

"Sergei insists that you get ideal croutons only if you cut them to the soundtrack from a TV show which says that I am a powerful agent of the West," Navalny quipped.

"He takes delight in this."

Supporters say that since returning from Germany in mid-January, where he had been treated for poisoning with Novichok, the Western-trained lawyer has taken his arrest, a series of court hearings and imprisonment on the chin.

Last month a court also convicted Navalny of defamation for calling a World War II veteran a "traitor" for appearing in a pro-Kremlin video.

He was ordered to pay a fine of 850,000 rubles ($11,500). His defence team is planning to appeal.