Samsung's heir apparent Tuesday bowed in apology for one of the group's flagship hospitals becoming an epicentre of the MERS outbreak as South Korea reported three new cases, but no additional deaths.

There are now 175 confirmed cases in what is the largest outbreak outside Saudi Arabia. Samsung Medical Centre in Seoul has accounted for about half of all confirmed cases in South Korea.

"Samsung Medical Centre has failed (to control) the infection and spread of the virus, causing great pain and concern to the people", said Jay Y. Lee, vice chairman of Samsung Electronics.

"I apologise, with my head bowed", he said before he bowed deeply in front of TV cameras in a live public apology.

He promised to thoroughly overhaul the medical centre. Its position as one of the country's most prestigious hospitals has been seriously tainted by the outbreak.

Lee, who heads the Samsung foundation that operates Samsung Medical Centre, also pledged to actively support the development of a vaccine against the MERS virus.

Lee's father and the chairman of Samsung Electronics, Lee Kun-Hee, has been bedridden in the hospital for more than a year after he suffered a heart attack.

According to South Korea's health ministry, two of the three new carriers came into contact with the virus at two different hospitals in Seoul, one of which was the Samsung Medical Centre.

The third case was a family member of another patient.

Separately, a 39-old woman who had been infected with the virus and recovered gave birth to a baby at Samsung Medical Centre on Tuesday, Yonhap news agency said.

Of the 175 confirmed cases, 27 have died, 54 have recovered and been released from hospital and 94 are still being treated, of whom 16 are on life support.

Some 2,805 people are still under quarantine, down around a quarter from Monday.

The first case was diagnosed in South Korea on May 20.