Ruling Janata Dal-United has issued a show cause notice to party member of legislative assembly Giridhari Yadav for mingling with Rashtriya Janata Dal strongman Mohammed Shahabuddin, who made caustic remarks against Chief Minister Nitish Kumar soon after his release from jail.

Earlier, the party said it is mulling action against Yadav.

"The JD-U leadership has taken note of our own MLA Girdhari Yadav being seen in the company of Shahabuddin at the time of the latter's release from jail," party spokesman Sanjay Kumar Singh told reporters.

"We cannot accept Yadav's conduct in being seen with the RJD strongman when he spewed venom on our Chief Minister Nitish Kumar ... the JD-U is mulling against him," he said.

Yadav represents Belhar assembly seat in Banka district.

Soon after being released from jail on September 10 after 11 years, the controversial RJD leader had described Nitish Kumar as 'chief minister of circumstances' and that RJD supremo Lalu Prasad was his only leader.

Not stopping at questioning Kumar's credentials for the chief minister's post, Shahabuddin had reportedly said on Sunday that he was not a mass leader.

Defending his meeting with the RJD strongman, Giridhari Yadav said he met Shahabuddin because of his personal relations with him.

"I have a friendship and personal relation with Shahabuddin and that's why I had gone to meet him (Shahabuddin) after his release from jail (in Bhagalpur)," Yadav said.

"Nitish Kumar is my leader and he has not spoken anything against him," he said.