The felines have racked up a bill of €1,017.42 since being taken to the Zwickau animal shelter in November.
Beate Zschäpe handed the animals to neighbours shortly before she allegedly blew up a flat used by the neo-Nazi terrorists on November 4.
She – and the cats – had lived in the Saxon town with two other neo-Nazis forming the National Socialist Underground.
A couple of days later she handed herself in to police and has been in custody ever since. An investigation is being conducted into a string of ten murders her companions claimed to have carried out before one shot the other and them himself after they were caught having robbed a bank.
The cats cannot be re-homed as they officially belong to Zschäpe, animal shelter head Claudia Ruf told the Sächsische Zeitung. She said the police authority of south western Saxony paid the bills until November 11, but then said she should ask the federal police for payment.
The federal police have denied all responsibility, and it seems Ruf will have to try sue Zschäpe for the costs.
The paper said Ruf would not release the names of the cats, in an attempt to prevent neo-Nazis from trying to adopt them.
She said the federal police had visited to take photos of the animals, and saliva samples, although she did not say whether they had asked any questions.