Did James Forrestal,America's first Sec.of Defense,commit suicide or was he murdered?

Did James Forrestal,America's first Secretary of Defense(before him the position was call Secretary of War) commit suicide or was murdered? And if he was murdered then by who? The Zionist? Forrestal was anti-Zionist,he thought it was a Soviet trick,and in 2006 the The Times of London reference newly declassified document revealing a serious attempt  by Menachem Begin(who of course,would later become Prime Minister of Israel) Irgun Gang to assassinate British Foreign Minister Ernest Bevin(also an anti-Zionist),had been thwarted by British intelligence in 1946.
Curiously Forrestal and Bevin where opposite poles politically Although a Democrat from New York Forrestal was man of the Right,made his money on Wall Street and very much anti-Communist.
Bevin was man of the Left,indeed, a Union leader member of Labor Party.
Also Zionist murdered Walter Guinness,1st Lord Moyne.He was very good friend of Winston Churchill,served in his Cabinet as Resident Minister in the Middle East out of Cairo,He work hard to get Jews out Germany and others areas like Poland occupied by Germany,however,he was against resettlement of the Jews in Palestine,instead he favored resettlement in other Arab lands most notably Jordan,Syria and Egypt.Moyne masses Jewish immigration would overwhelm the place and lead to much social unrest.Jordan,Syria and Egypt could take on the extra people without social unrest.For that he was murdered by the Stern Gang.The murder of Lord Moyne cause a split in Zoinist movement:for ChaimWeizmann,who would become first President(mostly symbol position)of Israel,said when murdered Lord Moyne they might have murdered my own son.
Also the Soviets might have murdered Forrestal or maybe he did commit suicide.