Yoshitaka Sakurada resigned after he hurt the feelings of the 2011 quake and tsunami victims.
Munoz's resignation follows a Reuters report which said that the Japanese automaker was looking into decisions made in the United States by Munoz.
Abdulaziz Bin Hassan has already resigned and is expected to step down next year.
Govt lawyer Suzana Atan maintains the appointments of Raus Sharif and Zulkefli Ahmad Makinudin were constitutional.
HRDF deputy chief executive Lim Kah Cheng will take over as acting chief executive with immediate effect.
The allegations included claims of “inappropriate comments and texts, and unwanted advances including kissing and groping,” the company said.
Two others also step down as part of Guocoland (Malaysia) Bhd's board rationalisation.
Britain's interior minister resigned on Sunday after Prime Minister Theresa May's government faced an outpouring of indignation over its treatment of some long-term Caribbean residents who were wrongly labelled illegal immigrants.
Taavi Roivas has publicly apologised for improper conduct during a party at a bar in a Kuala Lumpur hotel.
He cites personal and professional reasons for resigning, some six weeks after first expressing his intention to quit.