Update — March 31, 2016: Trump has walked back his comments saying doctors should be punished for illegal abortions, not women.

Republican front-runner Donald Trump has sparked outcry by saying he believed that if abortions are outlawed, women who undergo the procedure should face “some form of punishment.”

In comments that suggested he would somehow seek to overturn the right to abortion, cemented by the now famous 1973 Roe v Wade Supreme Court ruling, the tycoon suggested women who underwent the procedure would be penalised.

Mr Trump made the assertion during a Wednesday afternoon interview with MSNBC but did not address what the punishment would be. His comments were immediately criticised by women's rights campaigners, and Hillary Clinton said his remarks were "horrific and telling".

“Well, you know, you’ll go back to a position like they had where people will perhaps go to illegal places,” the former reality TV star said during the interview. “But you have to ban it.”

“There has to be some form of punishment,” added Mr Trump when pressed by interviewer Chris Matthews. When asked whether men should also face a penalty for abortion, as well, Mr Trump said he did not believe so.

Throughout the 2016 campaign, Mr Trump has reiterated his stance against abortion, and has expressed his desire to defund the public health non-profit, Planned Parenthood. He said the only exceptions should be in cases of incest, rape or if a women's life was in danger.

But Mr Trump has not always been so adamantly against the procedure and his position has changed.

In 1999, he told the interviewer Tim Russert that he supported women's right to choice.

The same year, he told the Associated Press: “I believe it is a personal decision that should be left to the women and their doctors.”

He also wrote, “I support a woman’s right to choose, but I am uncomfortable with the procedures,” in his book The America We Deserve, published in 2000.

After the interview, the Trump campaign released a statement from the candidate saying: “This issue is unclear and should be put back into the states for determination. Like Ronald Reagan, I am pro-life with exceptions, which I have outlined numerous times.”

While some 49 per cent of Americans believe abortion is “morally wrong,” according to data from the Pew Research Center, 51 per cent feel it should remain legal.