CLEVELAND, Ohio (AFP) - Found inside the house where Ariel Castro allegedly held three women captive for a decade was a note from 2004 in which he called himself "a sexual predator" in need of help, local media reported.

Castro, 52, was arraigned on Thursday for the rape and kidnapping of Ms Amanda Berry, 27, Ms Gina DeJesus, 23 and Ms Michelle Knight, 32, who all emerged on Monday from the unassuming Cleveland house owned by the former school bus driver.

Local television station WOIO investigative reporter Scott Taylor, on his Twitter feed, said the note was among dozens of pieces of evidence that police recovered when they combed the two-storey premises after the women's escape.

"I am a sexual predator. I need help," reporter Taylor quoted the note as saying.

In an apparent reference to captives, the note goes on: "They are here against their will because they made a mistake of getting in a car with a total stranger."

"I don't know why I kept looking for another," the note adds. "I already have 2 in my possession."

Reporter Taylor said Castro also wrote about wanting to kill himself and giving "all the money I saved to my victims".

Ms Knight was 20 when she was last seen in August 2002. Ms Berry disappeared on the eve of her 17th birthday in April 2003, while Ms DeJesus vanished in April 2004 at the age of 14.

Cleveland's deputy police chief Ed Tomba appeared to confirm the existence of the note when he was asked at a press conference on Wednesday by another local TV news channel if "a suicide note" had been found.

"That is another part of evidence that we recovered that I cannot comment on," deputy police chief Tomba said. "There were over 200 items taken from the home on Seymour Avenue. All of those items will be processed."