Davao City mayor Rodrigo Duterte was speaking about the killings of 36-year-old Australian Jacqueline Hamill and four other missionaries during a hostage situation at a prison in his city.
Soldiers stormed the prison after learning that a male hostage had been killed and female hostages were raped.
All 16 convicts and five of the 15 hostages died.
“What came to my mind was they raped her, they took turns raping her,” Mr Duterte said at a campaign rally last week.
“Why did I get angry — because she was raped? Yes, that’s part of the reason, but also because she was so beautiful and the mayor should have been first.”
His supporters attending the rally cheered at the comments, making Mr Duterte smile, as seen in a YouTube video.
But other politicians and social media users criticised the comments.
Australia’s ambassador Amanda Gorely tweeted that “rape and murder should never be joked about or trivialised” and “violence against women and girls is unacceptable anytime, anywhere”.
Mr Duterte has refused to apologise.