NEW YORK (CBSNewYork) — The man accused of attacking a Spanish tourist in City Hall Park last week may not be who he says he is.

John Yoos, 43, of Crown Heights, was arrested on July 30 after repeatedly striking 31-year-old Hugo Alejandre with the claw of a hammer, police said.

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WCBS 880’s Alex Silverman reports

Prosecutors are now investigating whether Yoos gave authorities a fake name.

A chess master in Canada came forward and believes Yoos is using his identity.

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The two share the same name and birth date.

The chess player, John C. Yoos, 43, of Vancouver, told investigators that he recognizes the suspect in the hammer attack as someone he met casually through friends about a decade ago but hasn’t seen since.

The Manhattan District Attorney’s office is looking into the false identity allegation, sources told WCBS 880.

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Yoos is due back in court on August 28. He is being held without bail on attempted murder and other charges.