Team Anna on Friday dismissed as "pretence" the CBI investigation into the irregularities in the coal block allocation and alleged such a probe is meant to give a "clean chit" to prime minister Mahmohan Singh.

"The CBI is under the government. Here the prime minister is accused. How will the CBI investigate the prime minister ? It is laughable, it is a pretence. We know the outcome of this probe. It will say that the prime minister has not done anything wrong. It will give clean chit to Singh," team Anna member Arvind Kejriwal told reporters in Ghaziabad.

Demanding an independent probe by a panel of three "honest" retired judges, he said why is the PM afraid of a probe if he is sure that he has not done anything wrong.

"We have said we are ready to be probed. Then why is the prime minister afraid. So there is nothing wrong, if people suspect that there was something wrong in this," he said.

Alleging that CBI is a "complete puppet" in the hands of the government, Kejriwal said disproportionate asset cases were going on against Mulayam Singh Yadav (SP), Lalu Yadav (RJD), Mayawati (BSP) and many other politicians for several years.

"However no worthwhile investigation has taken place. But Jagan Mohan Reddy, who is a political foe of the ruling UPA has been arrested in a very short period. This shows that CBI rather than acting as anti-corruption body is being used to serve the centre's political agenda.

"Can such CBI ever do an honest and independent probe into coalgate scam in which PM himself is accused? Can such a CBI do an honest investigation against the other 14 ministers?" Kejriwal said, adding this is why they were demanding probe in the case by a special investigation team.

He said they would not approach Supreme court if their demands are not met. "This is a political issue," he said.

Allegations of corruption were made by team Anna in the allotment of coal blocks especially during the period 2006-09 when Singh was handling the charge of coal ministry.

Reacting to the coal ministry rebuttal to the charges, he claimed the arguments were misleading and factually incorrect.

"While up to 2005, a total of 75 coal blocks were allocated, this number went up to 145 from 2006 to 2009.

Surprisingly, only one coal block has been allocated.

"Is the PMO saying the demand for coal was limited before 2005 and it increased suddenly between 2006 and 2010 and again came down to negligible after that. What are the factors that can explain such a trend in the economy?" he asked.