TEHRAN (FNA)- The great-great-great grandfather to former US president George W. Bush was deeply entrenched in the slave trade.

He was either personally leading or investing heavily in missions to kidnap Africans and bring them to America to work for no pay on plantations.

The finding was discovered by retired journalist and genealogist Roger Hughes and historian Josepeh Opala, who compared the signature of ruthless slave trader Thomas Walker and the known Bush ancestor of the same name.

The signatures, according to Slate, were nearly identical and often found at the bottom of letters where Walker would complain about the cost of his prisoners, RT reported.