The Central Bureau of Investigation on Friday registered a case of rape under section 376 of the Indian Penal Code against former Uttranchal minister Harak Singh Rawat after conducting preliminary probe into the 'unwed mother' episode that led to his resignation from the state Cabinet.

The case was registered after recording the statement of Indira Devi alias Jeeni, who alleged that he had established physical relationship with her against her wishes, CBI sources said.

She told the investigators the minister had promised her a job and lured her into the relationship, against her wishes, the CBI first information report said.

The minister said he would fulfil his promise within a month and lodged her in a government house, according to the CBI.

Jeeni delivered a baby in a government hospital on June 15. The incident created a flutter in the assembly and the opposition BJP demanded a thorough probe into the case.

Uttaranchal Assembly witnessed high drama from June 18 after the opposition parties alleged Rawat fathered the baby, prompting Chief Minister Narain Dutt Tiwari to recommend a CBI probe.

Initially reluctant to carry out the probe, the CBI began investigations into the case on July 12 and questioned the former minister, other officials, Rawat's domestic servants and Jeeni.