Donald Trump unwittingly tweets photo of murderer to claim support from Vietnam veteran
Donald Trump speaking at CPAC 2011 in Washington, D.C (Gage Skidmore/Flickr)

Donald Trump has been duped once again into retweeting a fake picture, this time of a “Vietnam vet” who is in fact a murderer.

The tycoon and U.S. presidential hopeful, who is under fire for criticizing the Vietnam war record of the 2008 Republican candidate John McCain, retweeted an endorsement from a person he believed to be the son of a Vietnam veteran on Monday night.

But Twitter users soon pointed out that the uniformed man in the black and white picture accompanying the tweet was Jeffrey MacDonald. The former U.S. army officer and doctor was convicted of murdering his pregnant wife, Colette, and two daughters in 1979. He is currently serving three life sentences.

The error is particularly embarrassing for Trump while he is still embroiled in the row over his controversial remarks about McCain, who was a prisoner of war in Vietnam.

On Saturday he said the Arizona senator’s “not a war hero. He’s a war hero because he was captured? I like people who weren’t captured.”

Rivals for the GOP nomination including the Florida governor, Jeb Bush, and the former Texas governor Rick Perry condemned Trump’s comments, while McCain said he should apologize to military families.

It is not the first time Trump, an enthusiastic retweeter, has been fooled into sharing pictures which are not what they seem.

In September last year, Trump was sent a photo of a couple by a Twitter user with the message: “My parents who passed away always said you were a big inspiration. Can you please RT for their memory?”

The picture was of the notorious British serial killers Fred and Rose West.

The business mogul’s gaffes are having little effect on his popularity in the polls. An ABC News/Washington Post poll released on Monday evening put support for Trump among Republicans and right-leaning independents at 24%, well ahead of his rival Republican primary candidates.