A coroner has accused the Home Office of “manipulating statistics” relating to deaths in immigration detention after it emerged that some records relating to the death of a detainee had been deleted.

Senior coroner André Rebello made the comments at the conclusion of an inquest at Liverpool and Wirral coroner’s court on Wednesday into the death of 35-year-old Polish man Michal Netyks.

Netyks was found dead at HM Prison Altcourse in Liverpool on 7 December last year. A jury concluded that the cause of death was suicide, partly contributed to by the immigration deportation process.

Netyks had completed a short prison sentence and had packed his bags ready for release when he received the news that, instead of being freed, the Home Office was going to deport him to Poland. He had lived and worked in the UK for 12 years.

The eight-day inquest heard that he died from a head injury after jumping from a floor of the building soon after he received the news that he was going to be deported.

Rebello said that partially redacted notes provided to the inquest by the Home Office indicated that records had been deleted by senior management. He said: “This needs investigation and an explanation as its effect is to manipulate statistics – it appears to be almost a denial of the facts.”

This is not the first time the Home Office has been criticised over its lack of transparency relating to deaths in detention.

The Guardian and other sources reported that there were 11 deaths in immigration detention last year – an all-time high. However, at the end of last month the Home Office for the first time ever published detention death statistics as part of new “transparency data”. Officials said there had only been four deaths last year.

The charity Medical Justice, which works for health rights for people in detention, questioned this Home Office data and received a response from the Home Office on 7 December, admitting that deaths of immigration detainees held in prisons, such as Netyks’, were not included in the data.

“Further work is ongoing to ensure any statistics published on deaths of those held solely under immigration powers in prisons … are aligned with wider statistics that are published on deaths in prisons and deaths in the detention estate,” the Home Office official stated.

Former prisons ombudsman Stephen Shaw raised concerns about the fact that the Home Office did not conform to the practice followed by the Ministry of Justice of publishing data on deaths of immigration detainees, when he gave evidence to the home affairs select committee in September 2018.

“I find it frankly odd and self-defeating that the Home Office doesn’t face the normal practice in the Ministry of Justice of making a statement when there is an apparently self-inflicted death in detention. I think they should do so routinely,” Shaw, who has carried out two comprehensive reviews into immigration detention for the Home Office, told the committee.

Arthur Netyks, Michal’s brother, said: “I miss my brother daily and the inquest has been a difficult time. A year on from Michal’s death, the family remains devastated by our loss and we find it worrying that there have been so many immigration detainee deaths in the same year.”

Deborah Coles, director of the charity Inquest, which has supported Netyks’s family, condemned the Home Office’s role in the death. “Their conduct has been part of a wider pattern of denial and obfuscation,” she said.

A Medical Justice spokeswoman said: “Medical Justice has repeatedly raised concerns about the lack of prompt and accurate reporting of people who die while held under immigration powers. The lack of such reporting shows a shameful disregard for those who die while held under immigration powers.”

The most recent death in immigration detention was on 2 December in Harmondsworth immigration removal centre near Heathrow airport, when Algerian Bouamama Redouan died. The Home Office has confirmed that the prisons and probation ombudsman is investigating the death.

A Home Office spokesperson said: “We would like to express our condolences to the friends and family of Mr Netyks.

“The Home Office is committed to increased transparency around those held in detention, and in November 2018 began publishing data on deaths in immigration removal centres.

“We are committed to extending this level of transparency to all those in immigration detention.

“However, given the very sensitive nature of the information and low numbers reported it is imperative that we ensure absolute certainty on figures before they are published.”