The New Brunswick government will join Ontario's independent investigation into why 1,176 cancer patients in the two provinces may have received watered down chemotherapy drugs.

A total of 1,176 cancer patients in New Brunswick and Ontario received a diluted mixture of cyclophosphamide, used to treat some cancers, such as breast and non-Hodgkin's lymphoma, Cancer Care Ontario announced on Tuesday.

In Ontario, Premier Kathleen Wynne has already ordered an independent investigation into how the chemotherapy drugs may have been diluted.

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Ontario Premier Kathleen Wynne, left, and Health Minister Deb Matthews announced an independent third-party investigation into chemotherapy errors on Thursday while touring a breast cancer research centre. (Frank Gunn/Canadian Press)

"I don't know exactly how this happened, but we obviously need to find out how it happened," Wynne said on Thursday.

More than 1,000 patients in Ontario may have received diluted chemotherapy drugs since March 2012.

Health Minister Ted Flemming told the legislature on Friday that New Brunswick has been invited to participate in the review.

"Ontario’s Ministry of Health invited my department to participate in an independent review of the quality control in the supply chain for compounded drugs. The government of New Brunswick is eager to contribute to this review," Flemming said in a statement.

"Like Ontario, we believe it important to understand how and why this occurred and prevent it from happening again."

Premier David Alward has said he’s "concerned" about the issue.

The Saint John Regional Hospital continues to contact patients affected by this failure to urge them to see their doctors. The hospital was notified of the error on March 28.

All of the cyclophosphamide in question has been removed and the Saint John Regional Hospital has secured appropriate supplies for subsequent treatment, officials said.

Flemming said the hospital is taking the appropriate steps to respond to the problem.

"I am heartened by the fact that the affected patients are in the capable hands of New Brunswick’s health professionals who are managing this situation with compassion and with competence," he said in the legislature.

"I also offer them my support as they carry out their work to care for their patients and seek out answers their patients deserve."