The multi-crore rupees fodder scam cases involving top politicians are progressing well in special courts in Bihar and Jharkhand, according to CBI Joint Director (Patna), R P Agrawal.

"The cases related to the scam involving top politicians are progressing well. In some of the cases, the prosecution witnesses are now being examined," Agrawal told reporters here.

"But it is difficult to specify a time-frame for conlusion of the trial as it will depend on courts," he said.

Of the 53 cases of the multi-crore rupees scam probed by the CBI, the courts in Jharkhand have already concluded trials in 34 in which 298 persons, including politicians and bureaucrats had been convicted and fined.

The remaining 18 cases were at different stages of trial, he said.

Agrawal said six new courts for CBI were being set up in Jharkhand and three in Bihar for ensuring speedy disposal of the cases.

RJD supremo Lalu Prasad and former Chief Minister Jagannath Mishra are named in the some of the cases in which trials are on in Bihar and Jharkhand.