Moscow isn’t ruling out the possibility that the British authorities are keeping Sergei Skripal and his daughter against their will, the Russian Foreign Ministry said.

Sergei Skripal, 66, was discharged from a British hospital last week after being poisoned in Salisbury on March 4. The recovery of his daughter Yulia, 33, was much quicker. She has been out of the hospital since April.

Doctors gave no details on Skripal’s condition or his current location. Yulia has not been seen in public since being discharged from the hospital, and the only statement from her was issued by British police.

Earlier in May, Russia said the UK denied consular access to Skripals, both Russian citizens, adding that it is not satisfied with London’s handling of the case. It also said it had little trust that Sergey and Yulia “are allegedly reluctant to communicate with us [Russian authorities] and that they reject medical examination with the participation of Russian specialists.”