The top oncologist at the center of disgraced Assembly Speaker Sheldon Silver’s corruption case has been given the boot from his job as head of a non-profit research center.

Dr. Robert Taub, until Friday the director of the Columbia University Mesothelioma Center, got $500,000 in state funding for the center in exchange for funneling sick patients to the Silver-affiliated law firm Weitz & Luxenberg, which in turn gave the allegedly crooked pol $3 million in referral fees, prosecutors said.

“The research and patient care activities of the mesothelioma center are being absorbed into the Division of Hematology/Oncology. Dr. Taub no longer serves as its director,” Columbia University Medical Center spokesman Douglas Levy said in a statement Friday.

Silver gifted Taub’s research center the dough in 2005 and 2007 from an $8.5 million pool of taxpayer money created by the state Health Care Reform Act, according to court papers.

Some of the grant money was supposed to go toward research related to the Sept. 11 attack.

When a change in law caused the HRCA fund to dry up, Silver allegedly told Taub the grant program had ended – but found other ways to compensate the cancer doc, Manhattan US Attorney Preet Bharara said Thursday.

Silver was credited with referring more than 100 clients to Weitz & Luxenberg – the majority of which were asbestos-related cases, court documents said.

Taub is cooperating with the investigation and will not be prosecuted, officials said.