A radiologist who was allowed to continue working despite being at the centre of a breast cancer scandal has failed to spot signs of the disease in another woman.
Dr Kong Fa Lan Keng Lun was found by the General Medical Council (GMC) to have deficiencies in his care of women at St Margaret's Hospital in Epping, where 6,000 scans had to be reviewed in 2005.
Now it has emerged he failed to properly treat another patient in 2012 while working at Ipswich Hospital.
The GMC, which originally placed conditions on Dr Lan's registration after the Epping scandal, has looked at the more recent case but decided to take no action against the doctor.
This is despite an independent radiology expert appointed by the GMC saying Dr Lan's care fell seriously below the standard that would normally be expected.
In the most recent case, the 46-year-old woman, from Suffolk, who does not wish to be named, attended Ipswich Hospital in June 2012 and September 2013.
She had been referred by her GP after suffering pain in her right breast for six months and nipple discharge - both signs of breast cancer.
Dr Lan carried out a mammogram and ultrasound but concluded there was no abnormality in either breast that would suggest the disease.
He said a small mass was most likely a small lymph node and did not order follow-up tests.
But 14 months later, the woman was urgently re-referred to the hospital by the same GP with the same symptoms and extreme pain.
She had another mammogram and ultrasound performed by Dr Lan, who then requested a biopsy.
This showed that the woman had breast cancer.
Fearing time was running out, the patient went to a private hospital and paid for a double mastectomy.
She told the Press Association: "I initially went to Ipswich because the pain I was suffering was unbearable - I was in agony.
"For a further 14 months I experienced horrendous swelling and pain that was so bad I passed out.
"The impact on my health of all this has been devastating.
"Every day is agony and I've been left with terrible health problems. I developed lymphedema. I still suffer from exhaustion. I'm still undergoing regular blood tests as my immune system is so low.
"It makes me so angry to think that I could have died because this cancer wasn't treated for 14 months after I was first seen by Dr Lan.
"But what makes matters worse is that he has failed patients before and been allowed to come back and carry on treating women."
The woman now takes a daily anti-cancer drug - anastrozole - which she says has debilitating side-effects.
She is suing Ipswich Hospital NHS Trust, claiming the 14-month delay in getting an accurate diagnosis caused serious health complications and has shortened her life expectancy.
The trust has admitted that during the initial consultation in June 2012, when Dr Lan identified a mass, more tests should have been arranged which could have shown the need for further investigation.
However, it disputes the claim that the delay has reduced the woman's lifespan.
Between October 2007 and October 2009, Dr Lan had 18 conditions placed on his registration by the GMC following the Epping scandal.
The GMC found Dr Lan had acted irresponsibly and inappropriately and provided inadequate care to a patient who was subsequently found to have breast cancer.
It also said Dr Lan failed to meet the screening standards expected of him in the care of a further eight women.
But the GMC also blamed the NHS trust, saying the unit was unsupported, understaffed and under-resourced.
In the more recent Ipswich case, an independent expert appointed by the GMC was critical of Dr Lan's examinations of the patient.
They said further investigations should have been carried out after the first appointment, while the second examination resulted in a failure to note several masses.
The expert also said there were significant failings in the way Dr Lan reported mammogram results.
But the GMC concluded that no further action was required.
It noted that Dr Lan has decided to take flexible retirement, although he will still report on some breast screenings.
Charlie Massey, chief executive of the GMC, said: "Where a doctor's conduct falls below the standard we expect and puts patients or the public confidence at risk, we can and will take action.
"In assessing whether a doctor is safe to continue practising, the law and case law dictate that we must take into account whether a doctor has admitted their mistake and taken action to address their shortcomings."
The patient's lawyer, Victoria Gofton, a clinical negligence specialist from Slater and Gordon, said: "We believe Dr Lan's failure to recognise the significance of the mass and order follow-up tests caused a 14-month delay in receiving treatment which she urgently needed.
"We are investigating if her condition was significantly worse as a result of the delay."
A spokeswoman for Ipswich Hospital, which employs Dr Lan, said: "The trust is aware of the ongoing investigations in this matter.
"As a legal claim is being pursued, the trust is unable to comment save to confirm that a response to the claim has been sent to the claimant's solicitor. We understand that the claimant's solicitor is investigating further."