A spokeswoman says Russian opposition leader Alexei Navalny is in satisfactory condition after being hospitalised for a severe allergy attack while in jail.

Navalny was taken to a hospital Sunday morning from the Moscow detention facility where he is serving a 30-day sentence for calling an unsanctioned protest against the exclusion from the ballot of independent Moscow City Council candidates.

His spokeswoman, Kira Yarmysh, says Navalny did not have a history of allergies and arrived at the hospital with severe facial swelling and red skin rashes.

Navalny was sentenced Wednesday to 30 days in jail for calling the protest of election officials voiding signatures independent City Council candidates needed to be on Moscow's ballot.

Yarmysh quoted a Facebook post by a personal doctor who was able to observe Navalny at the hospital where he was taken from a Moscow detention center.

"We cannot rule out toxic damage to the skin and mucous membranes by an unknown chemical substance with the help of a certain 'third person,'" the post read, adding that visiting doctors were not given full access to Navalny.

In 2017 Navalny was attacked with an antiseptic green dye that damaged vision in one of his eyes.

Russia's most outspoken opposition figure was detained by police Wednesday following a sweep of opposition candidates in the days leading up to anti-government demonstrations in the capital on Saturday.

Writing on Instagram, Navalny said he was detained as he left his apartment to go on a jog.

"People are right when they say that sport is not always good for your health," he quipped.

"I have been detained and am now at a police station wearing shorts like a stupid man."

He was sentenced to 30 days in prison for allegedly violating the country's protest laws. Navalny had called for demonstrations over the weekend after the disqualification of opposition candidates for Russian municipal elections.

On Sunday, a spokesperson for Navalny said on Twitter he was experiencing "severe swelling of the face and redness of the skin," adding that the cause of the reaction had not been determined but that Navalny had never experienced an allergic reaction before.

The spokesperson confirmed that he is being given all necessary medical assistance and is still under the protection of police officers.

It comes after more than 1,000 protesters were detained Saturday by police in the centre of Moscow, in a crackdown on opposition supporters demanding free and fair elections.

The local branch of the Ministry of Internal Affairs said at least 1,074 people were detained, while OVD-Info, an independent monitoring group, put the number at 1,127.

Thousands of Russians pledged to attend the protest in the capital Saturday, after Russian authorities banned a number of independent and opposition candidates from taking part in municipal elections in September.

Authorities stated that the candidates were barred from running because they had failed to obtain a sufficient number of signatures to be put on the ballot paper. Opposition politicians and supporters have rejected this allegation.

The decision has sparked a number of protests across Russia this month, including the largest demonstration in recent years last weekend, when 22,000 people took to the streets.