American Muslim preacher Yusuf Estes was denied entry into Singapore on Nov 24 for having expressed views the authorities say are "unacceptable" and "contrary" to the values of Singapore's multiracial and multi-religious society.
"Such divisive views breed intolerance and exclusivist practices that will damage social harmony, and cause communities to drift apart," the Ministry of Home Affairs (MHA) said in a reply to The Straits Times.
Mr Estes and his wife Khadijah had flown in to Changi Airport from Kuala Lumpur to join over 1,000 passengers on a spiritual cruise organised by Malaysia-based Islamic Cruise, which left Singapore Cruise Centre for Aceh in Indonesia last Saturday and returned on Wednesday.
Two other foreign preachers planning to speak on the same cruise had been banned from entering the Republic in October. MHA had said that Zimbabwean Ismail Menk preached "segregationist and divisive teachings", while Malaysian Haslin Baharim had described non-Muslims as "deviant".
The ministry confirmed this week that Mr Estes had been denied entry, in consultation with the Islamic Religious Council of Singapore. The cruise organisers had been seeking views about Mr Estes as a "possible speaker", MHA added.
It cited how Mr Estes, in a 2012 video, said it was "not part of Islam to celebrate others' holidays" or wish Christians "Merry Christmas" and Jews "Happy Hanukkah".
He also questioned the religious basis for Christmas in an article last December, and advised Muslims against "celebrating something that even the Christians should not be doing". Mr Estes, who converted from Christianity to Islam in 1991, also said the Bible had many contradictions, called it an unreliable text, and expressed "intolerant views of non-Muslims".
MHA said: "The Government will not allow religious preachers of any faith to run down other religions or spread ill will among the various religious communities."
The Government had in September announced its rejection of applications by two Christian preachers, one of whom was identified as Dutch Sheets from the US, to speak in Singapore as they had made denigrating and inflammatory comments about Islam and Buddhism.
Islamic Cruise's strategic and media communications director Kyairul Syahirin Ahmad told The Straits Times that Mr Estes was not engaged to preach on the ship, but invited as a guest to celebrate his 25th wedding anniversary, which coincided with the company's 25th cruise.
After he was turned away, Mr Estes flew back to Malaysia with his wife, and later posted a Facebook video in which he said they were "detained for quite a while". The couple were later flown to Aceh, where they performed prayers with cruise passengers at the Baiturrahman Grand Mosque on Monday.
In a half-hour speech that spanned topics from finding a spouse to fake news, he touched on his being denied entry. He said a stapled visa had left "a hole in the first number" of his passport, and this could have been an issue. He added that Singapore officials were "very polite" and "very nice", and dismissed suggestions that they were not allowed to eat or pray.
Some passengers were disappointed that Mr Estes was not on the cruise. Around 40 on board were Singaporeans, and Professor Sattar Bawany, who heads an executive coaching firm, was among them.
He said he supports the Government's move in clamping down on extremist preachers who could jeopardise religious and racial harmony.
But he added: "Mr Estes was entering Singapore as a tourist, not a speaker. The Government should exercise flexibility to allow such foreign preachers to pass through. As adults, we should be discerning enough to weed out any teachings that are divisive and undermine our racial and religious harmony. The choice should be left to us."
Correction note: In a previous version, the name of Yusuf Estes' wife was incorrectly stated. This has been corrected.