The health ombudsman took more than three-and-a-half years to investigate a complaint about the care of a teenage eating disorder patient who died following a string of failings, it has emerged.
The Public Administration and Constitutional Affairs Committee (PACAC) has expressed concern over the length of time the Parliamentary and Health Service Ombudsman (PHSO) takes to investigate complaints.
MPs said they had heard from families who were left "distressed and traumatised" by making a complaint to the NHS and the PHSO.
According to a new report by the committee, the PHSO took an average of 234 days to complete a full investigation in 2016/17.
While it is a reduction from 255 days the previous year, the MPs said the length of time taken to decide whether to investigate complaints, and then to carry out the investigation was "excessive".
The report cited the investigation into the death of Averil Hart (pictured) in December 2012.
The report into Miss Hart's death concluded that the 19-year-old died following a series of failures involving every NHS organisation that cared for her.
The ombudsman said that Miss Hart's death was an "avoidable tragedy" that would have been prevented had the NHS provided appropriate care and treatment.
But the PHSO's final report into Miss Hart's death was issued on 8 December 2017, three-and-a-half years after the original complaint had been made.
The PACAC report states: "We remain concerned at the length of time that PHSO investigations take to complete, not least because of the added distress this can cause to complainants.
"We are also clear that increasing the speed of investigations should not come at the cost of compromising their quality, and we therefore accept that delivering significant improvements may take some time."
MPs recommended that the PHSO publishes what average length of investigation it is aiming for and by when it intends to achieve it.
Meanwhile, the committee's report also criticises the "slow progress" on Government reforms to the complaint system.
Chairman of the committee Bernard Jenkin said: "Although it has much more to do, we are cautiously confident that the PHSO under the new ombudsman Rob Behrens is now on the right track.
"We welcome the personal commitment he has shown to rebuilding trust in the PHSO and improving the service it provides to the public.
"As a committee, we have heard from families left distressed and traumatised by making a complaint to the NHS and the PHSO.
"Too many people still have to complain to the ombudsman because public services don't deal with their complaint properly in the first place.
"The ombudsman and his staff do a difficult job. The Government can help them by introducing the reforms it has already promised. Ministers told our committee two years ago that improving NHS complaints was 'unfinished business'.
"It is now time for action, and for the Government to introduce the long awaited legislation they have already published."
Copyright (c) Press Association Ltd. 2018, All Rights Reserved. Pictured (c) Family handout / PA Wire.