ANKARA -- A Turkish prosecutor is preparing to try an MP known for her human rights campaigns on the grounds that she obstructed justice by not revealing the identities of prisoners who claimed to have been tortured, the Anatolia news agency reported on Tuesday.

The report said Prosecutor Bekir Selcuk had prepared a writ against Sema Piskinsut, a former head of the parliamentary human rights commission, demanding that her immunity be lifted so she can be tried for concealing information from the judiciary.

The charge stems from two reports the commission issued under Piskinsut's leadership consisting of interviews with prisoners in the eastern provinces of Erzurum and Erzincan.

In the reports, prisoners -- whose identities were not revealed but who were identified only through numbers -- claimed of torture at the hands of the Ankara police.

According to Selcuk's writ, Piskinsut declined to a request from the Ankara prosecutor's office to reveal the identities of the prisoners so that an investigation could be launched into the torture claims.

Piskinsut said she had promised the prisoners not to disclose their identities.

The prosecutor accused Piskinsut of concealing information from the judiciary and thus aiding the alleged torturers.

Under Turkish law, the writ will be sent to Parliament where lawmakers will vote on whether to lift Piskinsut's immunity.

Piskinsut, 49, won widespread praise during her three-year term as the head of the human rights commission with her daring investigations and midnight raids on police stations and prisons.