"We have every reason to believe this could be a question of the deliberate, forcible detention of a Russian citizen or possibly their coercion into a staged announcement," foreign ministry spokeswoman Maria Zakharova said.
While her whereabouts are unknown, Skripal said she is being supported by police officers who are keeping her informed of their high-profile investigation.
On Wednesday she said she did not currently wish to take up an offer of consular assistance from the Russian embassy, according to a note released by London's Metropolitan Police.
Yulia Skripal was visiting her father when the attack took place. Sergei Skripal was imprisoned in Russia for selling secrets to British intelligence in the 1990s but was exchanged in a spy swap in 2010.
Sergei Skripal's niece, Viktoria Skripal, has spoken to Russian media about the poisoning and last week saw her application to visit the UK rejected, with officials saying it did not comply with immigration rules.
Yulia Skripal on Wednesday cast doubt on her cousin's account, saying: "Her opinions and assertions are not mine and they are not my father's.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)