The British government has effectively barred Asmaa al-Assad, the London-born wife of ousted Syrian president Bashar al-Assad, from returning to the United Kingdom given that her UK passport is no longer valid, according to reports in The Times.

It remains unclear whether her passport has expired or if it was actively invalidated by the British authorities. Government sources suggest that her invalid travel documents, coupled with a refusal to permit entry on compassionate grounds, have left Asmaa unable to seek critical medical treatment in the UK.

Asmaa al-Assad, who was diagnosed with acute myeloid leukemia in May, is currently battling an aggressive recurrence of blood cancer. Earlier this month, The Telegraph reported that her chances of survival stand at just 50%. Isolated in Moscow, she is undergoing treatment for the disease under difficult circumstances.

Sources reveal that Asmaa was already in Russia receiving medical care before her husband fled to Moscow following the fall of his regime in a swift rebel offensive earlier this month. Her presence in Moscow, which is tied to her ongoing treatment, appears to be coordinated by her father, a prominent cardiologist. Reports indicate that both he and his wife have left their London residence to join their daughter in Moscow.