Patna: Former Bihar Chief Minister Rabri Devi and her elder son Tej Pratap Yadav on Monday expressed disappointment over the conviction of RJD leader Lalu Prasad in the fodder scam, saying they had thought he will be acquitted.

"I was expecting acquittal. It disappointed us. But we respect the verdict and have faith in judiciary," Rabri Devi told the media here.

Tej Pratap said he expected "relief" for his father. Nonetheless, "we respect the court verdict".

A special CBI court in Ranchi on Monday convicted former Bihar Chief Minister Lalu Prasad in the fourth fodder scam case but acquitted another former Chief Minister Jagannath Mishra.

Rashtriya Janata Dal (RJD) spokesperson Shakti Yadav said the party would challenge the verdict in the High Court.

Soon after the verdict, hundreds of RJD leaders and workers gathered outside 10, Circular Road, the official residence of Rabri Devi. Most said the RJD chief had been convicted due to political vendetta.

"How come Jagannath Mishra has been acquitted in a scam in which Lalu Prasad is convicted? Mishra was acquitted as he supported the BJP, which has 'managed' the CBI, and Lalu Prasad was convicted for fighting against them," RJD worker Mukesh Singh said.