KIEV, Ukraine - The office of jailed former Ukrainian Prime Minister Yulia Tymoshenko says a court has ordered her kept behind bars as part of a new investigation even if her current seven-year sentence is overturned.

The court ordered Tymoshenko arrested as part of a probe into the activity of an energy company she headed 15 years ago.

The ruling shows that Ukrainian authorities remain unbowed by strong Western pressure to release the country's top opposition leader. The U.S. and the EU have condemned her sentence on abuse of office charges as politically motivated.

The court made the ruling on Thursday at a session in Tymoshenko's jail cell where she's bedridden due to a back problem. Tymoshenko's office on Friday denounced the ruling as absurd.