LEIGH SALES, PRESENTER: What we know already about Bacchus Marsh Hospital in Victoria is shocking enough - 11 newborn babies dead in the space of two years. The public was reassured that the hospital's board and management had been removed and the head of the maternity unit had quit, but almost no information was revealed about what actually went wrong. Disturbingly, tonight 7.30 can reveal the true number of baby deaths is in fact 18. One obstetrician was sued at least a dozen times and other doctors were reported to authorities. Some of the mothers involved are tonight breaking their silence. Louise Milligan is the reporter.

LOUISE MILLIGAN, REPORTER: In early 2014, Caress Spiteri was four months pregnant when she had her dream wedding on Hamilton Island.

When she arrived at Bacchus Marsh Hospital five months later, Caress was unaware the hospital was already in the middle of a crisis. Her problems began with an overseas-trained locum.

CARESS SPITERI: When he went to induce me, after he put the drip in my hand, he stuck the hook in my urethra as he was doing the internal to break my waters.

LOUISE MILLIGAN: Baby Harley was born by emergency caesarean section. Afterwards, Caress was in excruciating pain. Despite this, she was discharged after three days.

CARESS SPITERI: My mum and my husband and myself were all begging them, pleading with them not to send me home because I couldn't get out of bed.

LOUISE MILLIGAN: Caress had two aggressive post-operative bacterial infections. She was unable to hold her baby or to move. Two days after she went home, a Bacchus Marsh midwife came to see her and said Caress was fine.

CARESS SPITERI: Two days after that I had the child maternal nurse come home for our first visit. When she pushed my stomach up to see my wound, it actually exploded and all the pus shot out to the side of my stomach. She then told me to pack my son's bags and get myself immediately to the hospital.

LOUISE MILLIGAN: Caress finally got to see the Bacchus Marsh head of obstetrics, Dr Surinder Parhar, at her two-week check-up.

CARESS SPITERI: He just grabbed my stomach like that and lifted it up. His thumb was actually in the wound and he told me that I got the infection because I was fat.

LOUISE MILLIGAN: In legal correspondence, Dr Parhar has denied saying this, but noted that obesity is a risk factor for infection. A week later, Caress had to have major corrective surgery at the Royal Women's Hospital. She still has an open hole in her stomach, 18 months later and is suing Bacchus Marsh Hospital.

JILL HENNESSY, VICTORIAN HEALTH MINISTER (Oct. 16, 2015): What has happened here has been a series of catastrophic failures by a number of parties that may have contributed to the very sad loss of young life.

LOUISE MILLIGAN: As horrible as Caress Spiteri's experience was, her baby lived. 11 other babies born in the Bacchus Marsh maternity unit in the same period didn't. In October last year, Health Minister Jill Hennessy revealed that seven of the deaths could've been prevented.

One of those in early 2013 should've raised a red flag. Solicitor Dimitra Dubrow represented the woman whose baby was delivered stillborn. The woman haemorrhaged badly during labour and was sent home with a life-threatening blood illness that wasn't picked up.

DIMITRA DUBROW, SOLICITOR, MAURICE BLACKBURN: A few days later unfortunately she had to be rushed to another hospital, where her condition was so serious that she almost died.

LOUISE MILLIGAN: Her doctor at Bacchus Marsh was Surinder Parhar and her condition became so serious that the head of obstetrics at Western Health, Professor Glyn Teale, reported Dr Parhar to the medical regulator AHPRA. The regulator failed to act on the notification for two years.

DIMITRA DUBROW: It's not good enough that it took two years. Our client is devastated about the time that it took AHPRA to make its finding because she questions and thinks about what could have been.

LOUISE MILLIGAN: All those other women.

DIMITRA DUBROW: All those other babies, all those other lives that could've been saved if the hospital had acted sooner or AHPRA had made its finding sooner.

LOUISE MILLIGAN: Late last year, Surinder Parhar resigned and the Victorian Health Minister sacked the board and management of Bacchus Marsh Hospital.

When asked about his role in the stillborn cluster, Dr Parhar told 7.30 he couldn't remember whether he was involved in any of those deliveries, even though they were just two to three years ago. But this story is much bigger than those 11 deaths and that one doctor.

What rang alarm bells during the analysis of the 2013-'14 stillborn cluster was that five of the seven babies died at full term during labour. That's rare in obstetrics and suggested error. It prompted the Health Department to ask independent reviewer Professor Euan Wallace to look back and see if there were any other avoidable deaths.

7.30 has discovered that there were seven other deaths dating back to 2003. One of the mums of those babies has spoken out for the first time.

Jacinta's painful memories of baby Ruby remain in this box. Ruby was Jacinta's second baby, delivered in 2009. She told medical staff at Bacchus Marsh that she was concerned during her pregnancy.

JACINTA: She didn't move. I just knew straight away that something was not right. I raised it with the doctor, I raised it with my midwives.

LOUISE MILLIGAN: No-one detected she had a condition called Intrauterine Growth Restriction that stopped her uterus from growing enough to accommodate her baby. Nevertheless, Jacinta continued to ask the midwives to investigate.

JACINTA: They'd hear her heartbeat and go, "Oh, there's her heartbeat. We found that." They'd put the CTG on and then they'd send me home, say, "She's moving. We can see that she's moving. She's fine. Go home."

LOUISE MILLIGAN: And how long would they have it on for?

JACINTA: It was not long. 10 minutes tops the last time that I went in.

LOUISE MILLIGAN: When she came back to Bacchus Marsh Hospital two days later, they discovered baby Ruby was dead. A distraught Jacinta was asked to drive to Ballarat Hospital 56 kilometres away to deliver the child. Bacchus Marsh didn't have the capability to do it.

JACINTA: (Becoming emotional) I screamed and I wanted just to not feel a thing. I didn't want to feel it. I didn't want to be there 'cause I knew what was coming. And I knew that it was all going to be real at the end of it, that my baby was not going to cry and that she was not going to look at me and that I would have to hand her to someone else and not take her home. It was one of the most painful, gut-wrenching things I've ever, ever been through in my life.

LOUISE MILLIGAN: Defective use of foetal heart monitoring equipment by Bacchus Marsh staff was one of the key concerns of Professor Wallace's review. The hospital's former chairman says the only monitor was 25 years old.

MICHAEL TUDBALL, FMR CHAIR, BACCHUS MARSH HOSPITAL BOARD: We've requested many times over the years, over the 13 or 14 years I was there, most recently in 2013 we wrote to the department saying particularly for maternity services, that investment was needed in equipment because we were outgrowing our capacity. The fundamental is that we were operating with old equipment in an old hospital - it's over 55 year old, that hospital and there's been no capital investment by any government at any level in that time.

LOUISE MILLIGAN: So far, the public story of what went on here at Bacchus Marsh Hospital has focused on one doctor, the head of obstetrics, Surinder Parhar. But in fact, there were a number of doctors who were involved in avoidable stillbirths. At least three of the doctors here have been the subject of notifications to the medical regulator, AHPRA, and two of them have had restrictions placed upon their practice.

One of those is Claude Calandra. Dr Calandra has been working in hospitals in Melbourne's west for years. Calandra is a very familiar name to plaintiff lawyer Anne Shortle. He's been sued more than a dozen times for alleged medical negligence.

ANNE SHORTALL, PLAINTIFF LAWYER, SLATER & GORDON: I've printed a list off from the County Court of a number of 13 writs which have been issued over 14 years. ... It's very unusual. There are very few doctors that would've had that number of claims made against them over that period of time.

LOUISE MILLIGAN: All of those cases were settled.

TRACY DANSKIN-ANTHONY: I really do not understand why they keep him practising. He shouldn't be allowed.

LOUISE MILLIGAN: Dr Calandra delivered Tracy Danskin-Anthony's baby daughter Tommi at Werribee Mercy Hospital in 2001. Tracey says she heard the nurses saying the baby was in distress during the labour. Nevertheless, Dr Calandra delivered her baby naturally.

TRACY DANSKIN-ANTHONY: When she was born, he put her on my chest and I noticed she wasn't crying and she wasn't moving. And I'm like, "Something's wrong. She's purple." She wasn't crying and she wasn't moving. And I said to him, "What's wrong?," and I remember just thinking, "Just breathe, just breathe."

LOUISE MILLIGAN: Tommi was taken away and placed on life support. She died a few days later.

TRACY DANSKIN-ANTHONY: Six weeks later when I went there to get my records of labour, I bumped into him and I said to him, "What happened?" And he said, "Oh, well, these things happen." "Oh, well."

LOUISE MILLIGAN: Claude Calandra was not responsible for any of the stillbirths made public last year, but his track record of extensive litigation raises questions about why he was still at Bacchus Marsh.

The case brought against Claude Calandra by this little boy's family has been put on hold. Under Dr Calandra, Luca Weir's mother Candice says she laboured for five days with her baby.

CANDICE WEIR: He was in distress. His heart was slowing down and then rapidly speeding up, slowing down to the point of almost stopping.

LOUISE MILLIGAN: What did Dr Calandra tell you?

CANDICE WEIR: That he was grabbing onto his cord and causing himself to pass out.

LOUISE MILLIGAN: When Luca was finally born, Candice Weir says he showed signs that he'd been without oxygen for some time.

CANDICE WEIR: 11 to 13 minutes that I know of. They told me that he'd had to be taken to intensive care unit, put on a drip. He was dry, he was without - his waters had been broken for 72 hours, so he had an infection, he had sepsis - blood poisoning - and I had blood poisoning.

LOUISE MILLIGAN: The mother of three soon noticed worrying behaviour by her infant son, like repetitively banging his head against his cot. Luca didn't walk until he was two and a half. At five, the school asked for him to be assessed for autism and ADHD. Candice Weir has been advised by a lawyer to have his brain scanned when he's 10 to see if his behavioural and speech delays were caused at birth.

CANDICE WEIR: I get a sick feeling in my stomach thinking about that and what happened there. It does, it brings up a sick feeling in my stomach.

LOUISE MILLIGAN: 7.30 approached Claude Calandra, but he declined to speak to us. Patient complaints about Dr Calandra prompted the medical regulator to place restrictions on his registration for six months in 2012. He continued to practise at both Werribee Mercy and Bacchus Marsh.

Bacchus Marsh Hospital wouldn't tell us what it knew about the restrictions or the writs, but the hospital's former chairman says he has no idea about them.

MICHAEL TUDBALL: I think there was a breakdown in process as far as any investigations that were going on to doctors or medical people at Bacchus Marsh that had no requirement to inform anyone at Bacchus Marsh, so you're operating in a fair vacuum.

LOUISE MILLIGAN: 7.30 has established that at least three doctors apart from Dr Parhar who were involved in some of the avoidable baby deaths are still practising at Bacchus Marsh Hospital and AHPRA is now doing a wider investigation into those and other doctors at the hospital.

Meanwhile, the women of Bacchus Marsh wonder if they can really trust in the care provided by the area's only maternity hospital.

JACINTA: Lots of things can go wrong in pregnancies and every woman has the same right to the same care, no matter where they live. Because the result of them not getting the same care is that you end up with a situation like this.

LEIGH SALES: Reporter Louise Milligan and producer Andy Burns with that story.