Patna: The Bihar BJP has issued a show cause notice to party MLC Sachidananda Rai for launching a vitriolic attack on chief minister Nitish Kumar, after reports surfaced that his government sought details of office-bearers of the RSS and its affiliates from different districts.

The saffron party's disciplinary committee president (Bihar) Amarendra Pratap Singh issued a notice on Sunday, asking Rai to reply within 10 days as to why disciplinary action should not be taken against him.

Although it makes no mention of any particular instance of indiscipline, the notice criticises Rai for repeatedly issuing "statements in your personal capacity, at odds with the party's official stand" and charges him with "undermining the sanctity of the National Democratic Alliance".

Rai had reacted with outrage when the news of a letter, issued by the special branch of the police to district units two months ago, surfaced last week.

"Our party must be careful of the intentions of chief minister Nitish Kumar, who holds the home portfolio. We should note the timing of the letter," Rai said.

"It was around the same time when he had thrown a tantrum and refused to join the Narendra Modi government at the Centre, despite contesting the Lok Sabha polls as an NDA ally," the MLC said.

Seeking to know the nature of relationship between the BJP and its ally JD(U) of which Kumar is the president, Rai had also reportedly said he was only interested in remaining the CM irrespective of which alliance he is part of.

The special branch later clarified that details were sought in view of intelligence inputs on functionaries of the RSS and affiliates in Bihar facing threat to their lives.

It also found that the language used in the letter, issued by an SP rank officer, "objectionable" and said he may face action for the same.

Several BJP leaders, including Union minister Giriraj Singh, have questioned the issuing of such a letter."Why, with a former RSS activist like Sushil Kumar Modi as deputy chief minister, the state needed to collect information in this fashion?" Singh said recently.