NEW YORK (AFP) - A wrongfully convicted New Yorker who served more than two decades behind bars had a heart attack the day after he was released, his lawyer said on Saturday.

Mr David Ranta was sentenced to 37 years in prison after being convicted in 1991 of killing an Orthodox Jewish rabbi during a botched robbery. He always maintained his innocence and was freed on Thursday after 23 years.

CNN quoted Mr Ranta's lawyer Pierre Sussman as saying that Mr Ranta suffered a heart attack late Friday.

"My office is happy to report that he's been stabilised and is being treated in cardiac intensive care at a metropolitan hospital," Mr Sussman said in a statement.

Mr Ranta was released after the Brooklyn District Attorney's Office announced an internal probe had found evidence unavailable during the trial that cleared him.

Upon being declared free by a judge, Mr Ranta told reporters he was overwhelmed.