Ukraine on Monday allowed jailed opposition leader Yulia Tymoshenko to receive medical treatment outside prison amid widening European concerns for the former pro-Western prime minister's health.

The general prosecutor's office said it was granting a request from the former Orange Revolution leader's party for her to obtain medical leave to treat debilitating pain from a slipped disk in her back.

The chief prosecutor's statement said Tymoshenko could undergo observation and treatment in a "specialised medical facility."

The statement did not clarify whether Tymoshenko had been granted permission to received treatment abroad, but a spokesman for the office said it was referring specifically to medical facilities in Ukraine.

Tymoshenko had earlier requested treatment in a German clinic.

Berlin said on Saturday it was in talks with Kiev to determine whether Tymoshenko could receive care outside Ukraine.

The charismatic but divisive leader is serving a seven-year sentence after being convicted of abusing her power while serving as premier.

She has refused prison care and accused Ukrainian doctors of bias and working under the orders of President Viktor Yanukovych -- an arch rival who defeated her in a bitterly-fought 2010 election.

Tymoshenko was detained in August and jailed in October over her decision to sign a 10-year gas deal with Russia, considered unfavourable to Ukraine.

She is now also being investigated in a number of other probes that she describes as personal revenge by Yanukovych.