Public Prosecutor Rajiv Mohan submitted to the court that that though they have completed their investigations in some aspects of the case, their overall probe into the scam is not yet complete.
He said the police is still awaiting Lok Sabha Speaker's sanction to prosecute BJP MP Ashok Argal.
The supplementary charge sheet was filed in the court of Special Judge Sangita Dhingra Sehgal by the Crime Branch of Delhi Police.
It contains no new names as the accused and is in continuation with the investigations carried out earlier before filing the first charge sheet on August 24, the prosecutor said.
He added the supplementary charge sheet also contains bank statements of some of the accused as annexures.
The Delhi Police had, in its first charge sheet, accused Samajwadi Party leader Amar Singh and L K Advani's former aide Sudheendra Kulkarni of "conspiring" and "masterminding" the cast-for-vote scam to bribe some MPs ahead of a confidence vote in Lok Sabha in 2008.
It had also named two former BJP MPs Faggan Singh Kulaste and Mahabir Singh Bhagora along with Sanjeev Saxena, former aide of Amar Singh and Suhail Hindustani, alleged BJP activist, who are in judicial custody.
