The company behind HS2 was “dishonest and misleading” in dealing with a compensation claim from a homeowner whose property needed to be compulsorily purchased, a report said.

HS2 “failed to properly engage and communicate” with a complainant whose family home, business and smallholding was on the planned route between London and Birmingham.

The report, from the Parliamentary and Health Service Ombudsman, said HS2 had misled the complainant, causing them “severe stress and worry which impacted on their health and family life for over four years”.

In our view, these are serious injustices that will have a lasting impact

In a statement published by the BBC, the firm said there had been “significant changes to HS2 Ltd, our responsiveness, and the complaints handling approach” over the last four years since the case was raised.

HS2 had previously been criticised for its poor engagement with the same community near Lichfield and “should have been repairing an already fractured relationship following our 2015 report”, ombudsman Rob Behrens said.

Then, HS2 was told to pay thousands of pounds for a “catalogue of errors” in dealing with residents’ pleas to be helped to stay together when their homes were demolished to make way for the rail line.

The latest report, published on Thursday, said HS2 should apologise to the complainants – referred to as Mr and Mrs D – for the “delay, frustration, inconvenience and distress their serious maladministration” caused the couple.

It added: “While HS2 were not responsible for Mr and Mrs D having to sell their family home to make way for the proposed railway, we can see HS2’s actions exacerbated the impact on Mr and Mrs D’s stress levels and health.

“In summary, HS2’s handling of Mr and Mrs D’s case caused delay in progressing elements of their case, unnecessary levels of stress and anxiety as well as giving Mr and Mrs D cause to doubt HS2’s honesty and sincerity when responding to their concerns.

“In our view, these are serious injustices that will have a lasting impact on Mr and Mrs D.”

The new line will connect London and Crewe with the first phase, to the West Midlands, set to open between 2029 and 2033.

The report added: “HS2 was dishonest, misleading and inconsistent, and failed to follow its own processes when negotiating compensation claims with the complainant for their family home.

“This meant there was a breakdown of trust and it undermined the complainant’s faith that they would be treated fairly.”

The HS2 statement published by the BBC added: “We understand that residents did not choose to live along the line of the route and that for many the process of having their homes acquired will be distressing.

“HS2 Ltd endeavour to treat every land and property case with respect and compassion, while also recognising our obligations to spend taxpayers money appropriately when agreeing compensation.”