Moscow's Simonovsky district court has decided not to suspend "retrospectively" the custodial sentence of opposition politician Alexei Navalny by the 18 and half hours that he spent in hospital.

"The court finds no grounds for suspending Navalny's arrest," judge Valentin ruled.

The suspension had been requested by the head of the holding facility N1 where Navalny is serving his 30-day jail sentence. The jail chief had asked the court "to consider the matter of suspending execution of sentence for the duration of Navalny's stay in the hospital and determine a procedure for further execution of sentence."

Navalny spent 18 hours 35 minutes outside the jail, the request said.

After today's ruling, Navalny should be freed at 8:50 a.m. Friday, August 23.

Navalny and his lawyer Vadim Kobzev had asked the court to turn down the request.

The jail chief's having raised this issue with the court was unlawful because "by law, the matter of suspended execution of administrative arrest must be considered before, not after, the suspension," Kobzev said.

"Not for one minute" had security guards left Navalny on his own in hospital, he said.

His claim was supported by Navalny who said that, "from the very start and right up to the end [he was] in the presence of police officers in great numbers."

"Had the holding facility somehow relieved the security guard and decided to suspend the arrest, I should at least have been notified about that. It was impossible to release me from under arrest with me not being in the know," Navalny said.

Navalny was sentenced to 30 days in jail after the Simonovsky court found him guilty of a repeat violation of the rules for organizing or conducting mass public events. The ruling was upheld by Moscow City Court on July 30.

It was established that during a rally (permitted by authorities) in Sakharov Avenue on July 20 and on his Facebook page Navalny called on citizens to join an unsanctioned rally on July 27 to support independent candidates for the Moscow City Duma.

On July 28, Navalny was taken from the jail to the hospital N64 where he was diagnosed with contact dermatitis. He was released the following day.

Navalny said he might have been poisoned and filed this claim with the Investigative Committee, asking it to check whether the jail staff abused, exceeded, or neglected their duties.