Prosecutors in Russia could remove a one-year-old boy from his parents' custody because they allegedly took him to an unauthorised protest and let another demonstrator take care of him.

The parents, Dmitri and Olga Prokazov, have been questioned by the Russian Investigative Committee.

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Their lawyer, Maxim Pashkov, told the Interfax news agency they denied participating in the July 27 protest.

The investigative committee is considering a criminal case against the couple on the charge of placing a child in danger, which carries a prison sentence of up to a year.

Russian media report the parents are accused of allowing a protester to hold the child. The reports say the protester is being sought for on the charge of involvement in mass disorder.