Mumbai, Dec 4 (PTI): Mumbai police has sought sanction of Maharashtra Assembly Speaker Dilip Walse-Patil to prosecute senior Congress leader Kripashankar Singh under the Prevention of Corruption Act in connection with a disproportionate assets case against him.

A letter seeking the Speaker's nod to prosecute Singh, MLA from Kalina and a former Mumbai Congress chief, was sent recently, sources in the city police said on Tuesday.

Under the Prevention of Corruption Act, the Speaker's prior consent is required by the investigating agency to prosecute an MLA.

Singh had resigned as Mumbai Congress Chief after the Bombay High Court had on February 22, 2012, directed the city police Commissioner to prosecute him and his family members for criminal misconduct under the PCA.

Police had in February last year registered an FIR against Singh and his family members for allegedly possessing assets disproportionate to their known sources of income.

The Congress leader and his family had approached the Supreme Court, which on March 13, 2012, refused to stop the investigation but put an interim stay on the process of attachment and seizure of their properties.

It had asked the Mumbai Police Commissioner to conduct an independent probe and collect documentary evidence regarding all movable and immovable properties of Singh and his family, including his wife, son, daughter-in-law and daughter, while seeking a report in a sealed envelope.

It also restrained the politician and his family members from "alienating, transferring or dealing with properties" enumerated in the petition against them during the pendency of the case in the court for which an undertaking was given.

Challenging the High Court's order for prosecution, they said it was passed on a petition which was politically motivated.

The High Court had passed the order on a public interest litigation by activist Sanjay Tiwari and others, who alleged that the Congress MLA had amassed wealth beyond his known sources of income.

Tiwari had claimed that Singh was close to former Jharkhand Chief Minister Madhu Koda, who was himself involved in an alleged multi-crore rupees hawala scam.