Results of an independent investigation into maternity care at Homerton University Hospital could be published this month following pressure from an anonymous group of whistleblowers alleging there have been avoidable deaths of mothers and babies.

The claims have been strongly refuted by Homerton University Hospital NHS Foundation Trust, which launched its own investigation after the group – who dubbed themselves the “unhappy midwives” – flagged up concerns in 2012 about several unspecified serious incidents.

Minutes from the trust’s board meeting in September 2013 reveal concerns were investigated by the hospital’s former chief executive Nancy Hallett and chief midwifery nurse Sheila Adam, and the cases in question were concluded to have been “appropriately managed”.

The minutes also note that reviews by the Care Quality Commission (CQC), the NHS Litigation Authority and a supervisor of midwives did not found “significant concerns”.

But campaigners continued to complain and launched an online petition calling for the resignation or removal of the senior maternity management at the hospital in Homerton Row.

The group also raised concerns with the CQC, which investigated the hospital last year, claiming mothers and babies receiving treatment at the hospital are still at risk.

The City and Hackney Clinical Commissioning Group (CCG) launched an investigation last October to identify specific incidents from the information provided by “unhappy midwives”.

A midwifery lecturer and head of midwifery, both from the Midlands, have spent three days at the hospital to compile a report which the CCG is finalising.

A CCG spokesman said: “This should be ready in June, at which point we will ask the Homerton to formally respond.”

A spokesman for Homerton University Hospital said: “We look forward to receiving the review report and responding to it.”