(Adds second statement from Prince Ali)

ZURICH, May 27 (Reuters) - Prince Ali Bin Al Hussein, the man challenging Sepp Blatter for the most powerful job in world soccer, said the latest corruption scandal involving the sport's governing body FIFA was proof that change was needed.

An outspoken critic of Blatter who has vowed to clean up the sport if he can oust him as president, Prince Ali said was deeply saddened by the news that six high-ranking soccer officials, including two FIFA vice-presidents, had been arrested by Swiss police and detained pending extradition to the United States.

"Today is a sad day for football," Prince Ali said in the first of two statements he issed on Wednesday.

The Swiss Federal Office of Justice said the arrested officials were suspected by U.S. investigators of having received or paid bribes amounting to millions of dollars.

The timing could not have come at a worse time for Blatter, who is being challenged by Prince Ali for the FIFA presidency.

Blatter is attempting to secure a fifth term at the helm despite widespread criticism of his leadership during a period when the sport has been dogged by allegations of corruption.

Prince Ali was encouraged to stand against Blatter by colleagues disenchanted with the Swiss administrator.

The vote will take place during the FIFA Congress on Friday with Blatter widely tipped to win although it remains to be seen whether Wednesday's latest scandal will have an impact on the ballot.

"We cannot continue with the crisis in FIFA, a crisis that has been ongoing and is not just relevant to the events of today," the Jordanian said.

"FIFA needs leadership that governs guides and protects our national associations. Leadership that accepts responsibility for its actions and does not pass blame.

"Leadership that restores confidence in the hundreds of millions of football fans around the world."

(Writing by Julian Linden in Singapore; Editing by Giles Elgood) ((julian.linden@thomsonreuters.com; +65 9726-4394; Reuters Messaging: julian.linden.thomsonreuters.com@reuters.net))

Keywords: SOCCER FIFA/ARRESTS ALI