A couple of days ago, Wikileaks released 1.7 million diplomatic cables from 1973-76, and many others have been noting interesting ones. (See this excellent analysis by Lee Smith in Tablet.)
Here's one I found from March 1973:
1. US NEWSMAN HAS GIVEN EMBASSY ON CONFIDENTIAL BASIS TEXT PURPORTED BUT UNRELEASED INTERVIEW "SOMEWHERE IN GERMANY" WITH BSO MEMBER BY GERMAN TV NEWSMAN.
2. DURING INTERVIEW, BSO MEMBER STATES
(A) NO DISTINCTION BETWEEN AL FATAH AND BLACK SEPTEMBER,
(B) BSO RECEIVES $80-85 MILLION ANNUALLY FROM LIBYA ($30 MILLION), SAUDI ARABIA ($15 MILLION), GULF STATES ($10-12 MILLION), ALGERIA ($5 MILLION) AND PRIVATE SOURCES. STATED EGYPT AND SYRIA PAY NOTHING,
(C) ARAFAT RECEIVED $5 MILLION " BONUS" FROM LIBYA FOR MUNICH OPERATION AND HAS PRIVATE BANK ACCOUNT IN SWITZERLAND,
(D) 10-15 EUROPEANS INCLUDING GERMANS ARE PART OF BSO, AND
(E) BSO WEAPONS AND AMMUNITION COME FROM USSR, PRC, EGYPT, SYRIA AND ALGERIA.Keep in mind that at this time, Arafat strenuously denied any connection between Fatah and Black September, which was responsible for a string of terror attacks (including killing Americans in Khartoum.)
The State Department knew very well that Arafat was lying. Even these cable show that clearly (here's one where Idi Amin stated that Arafat assured him that Black September would not disrupt an OAU meeting.)
Given all this, the interview sounds like the real deal.