ROSTOV-ON-DON, May 6. /TASS/. Russian pilot Konstantin Yaroshenko, sentenced to 20 years in jail in the US, has been put into solitary confinement for a month, his wife told TASS on Sunday.

According to Viktoriya Yaroshenko, her husband said this in their telephone conversation on Saturday, the first since April 30.

"I understand the situation this way - when Konstantin said in April that he saw provocations from the [prison] chief, he said it just in time to stop this. Then they (prison administration - TASS) decided to act their own way - seemingly not accusing Konstantin of anything, putting him into the ward with care, however disregarding Konstantin’s grave condition - he has dysentery and has been suffering from diarrhea for the past month-and-a-half," she went on to say.

"He told me yesterday that he won’t be able to contact me over the phone for 30 days, he is not allowed to make calls. Thirty 30 days of solitary confinement, he said," Viktoriya Yaroshenko stressed, adding that her husband had started complaining of stomach and heart aches, as well as persistent dizziness.

On Saturday, pilot’s lawyer Alexei Tarasov told TASS that he could not reach him over the phone. The lawyer says the prison administration has provided no explanations either to him or to Russian diplomats.

Viktoriya Yaroshenko plans to appeal to the Consulate General for help to ensure prison medical assistance to her husband. "He could buy rice in an ordinary ward and eat it, he was drinking water all the time. Now he has no water, he gets coffee with milk, but dairy products are categorically prohibited during diarrhea," she added.

Russian pilot Yaroshenko was sentenced to 20 years in jail in the United States on September 7, 2011. He had been brought to the United States from Liberia after being arrested on May 28, 2010. Agents from the US Drug Enforcement Administration operating in disguise allegedly exposed his criminal intentions to transport a large batch of cocaine.

Yaroshenko underwent a surgery last year, but proper post-operation treatment was denied to him.

Russia has numerously requested the United States to release Yaroshenko.