State Sen. John Sampson threatened to “take out” cooperators before his 2013 arrest, a witness testified Thursday at the Brooklyn politician’s corruption trial.

“He told me that if ‘I ever find out who the cooperators are I would take them out,’ ” Brooklyn businessman Edul Ahmad told jurors. “When he said that to me it kind of scared me . . . I got scared for my life.”

Prosecutors claim Sampson embezzled $188,500 from foreclosure deals he coordinated while acting as a court-appointed referee and then took a loan from Ahmad to cover the shortfalls.

He then gave Ahmad political favors in exchange for the cash, according to court papers.

Citing statute-of-limitations issues, Brooklyn federal Judge Dora Irizarry tossed the embezzlement charges against Sampson, but he still faces up to 20 years in prison for allegedly waging a coverup.

Ahmad — who flipped on his old pal after getting busted for mortgage fraud — also testified that Sampson said the probe against him was part of a racially motivated “witch hunt to prosecute black politicians.” Selim Algar