A business offering a home to a Ukrainian refugee family said waiting to be matched and the visa process were “unacceptably” long.
Costello Medical has had a flat ready in Cambridge since March.
It was matched with Viktoriia Ostapets and her relatives in September via a charity, but the family were still waiting for their British visas.
The government said it was having to carry out extra checks, due to Ms Ostapets bringing her young niece.
Ms Ostapets applied to come to the UK from Lviv 10 weeks ago with her injured father, daughter Elina and niece Renata, who she is legally responsible for.
The Ukrainian city is near the Polish border, but was hit by missiles not long after the Russian invasion began in February, with fresh strikes last week.
The British government said it had to ensure two forms of parental checks were carried out before a visa could be issued for her niece.
The flat owned by Costello Medical, an international communications agency, is normally used by visiting medical staff.
The government began its Homes for Ukraine scheme in March, to find host families and businesses in the UK for refugees.
“More than 142,000 Homes for Ukraine visas have been issued and we are working at pace to approve visas as quickly as possible,” the Department for Levelling Up, Housing and Communities said in a statement.
It added it was aware of the family’s case, but said: “It is only right enhanced safeguarding checks take place before we issue visas to under-18s travelling without their parent or guardian.
“As agreed with the Ukrainian government, visas will only be issued if they have the correct parental consent and once these checks have taken place.”
