TALLINN, Estonia >> The whereabouts of Russian opposition leader Alexei Navalny were unknown today as officials at the penal colony where he is serving his sentence told one of his lawyers that he is no longer on the inmate roster, his spokeswoman said.

It had been nearly a week since the spokeswoman, Kira Yarmysh, had contacted Navalny. Prison officials “refuse to say where they transferred him,” she said in posts on X, formerly known as Twitter.

A Navalny lawyer waiting at another penal colony in the region where he could have been transferred was told the facility had no such inmate, Yarmysh said.

“It remains unclear where Alexei is,” she wrote.

Navalny has been serving a 19-year term on charges of extremism in a maximum-security prison, Penal Colony No. 6, in the town of Melekhovo in the Vladimir region, about 230 kilometers (140 miles) east of Moscow. He was due to be transferred to a “special security” penal colony, a facility with the highest security level in the Russian penitentiary system.

Russian prison transfers are notorious for taking a long time, sometimes weeks, during which there’s no access to prisoners and information about their whereabouts is limited or unavailable. Navalny could be transferred to one of a number of such penal colonies across Russia.

Yarmysh earlier today said that Navalny was due to appear in court that day via video link but did not, and that it has been six days since his lawyers or allies last heard from him.

Navalny, 47, has been behind bars since January 2021. As President Vladimir Putin’s fiercest foe, he campaigned against official corruption and organized major anti-Kremlin protests. His arrest came upon his return to Moscow from Germany, where he recuperated from nerve agent poisoning that he blamed on the Kremlin.

Navalny has since been handed three prison terms and spent months in isolation in the penal colony in the Vladimir region for alleged minor infractions.

He has rejected all charges against him as politically motivated.

Last week, Yarmysh said that for three days in a row Navalny’s lawyers spent hours at the penal colony waiting for permission to visit him, only to be turned away at the last minute. Letters to the politician were not being delivered, and he didn’t appear at scheduled court hearings via video link.

Yarmysh said Friday that the developments were concerning given that Navalny recently fell ill: “He felt dizzy and lay down on the floor. Prison officials rushed to him, unfolded the bed, put Alexei on it and gave him an IV drip. We don’t know what caused it, but given that he’s being deprived of food, kept in a cell without ventilation and has been offered minimal outdoor time, it looks like fainting out of hunger.”

She added that lawyers visited him after the incident and he looked “more or less fine.”

Concerns about Navalny reverberated across the globe. White House national security council spokesman John Kirby today said that Navalny “should be released immediately” and “should never have been jailed in the first place.”

“And we’re going to work with our embassy in Moscow to see how much more we can find out,” Kirby said.