A mother whose son died while under the care of a heavily-criticised NHS trust was called a "vindictive cow" in a voicemail message apparently left by a care worker.
Dr Sara Ryan has campaigned for justice since her teenage son, Connor Sparrowhawk, drowned at the Southern Health-run Slade House in Headington, Oxfordshire in 2013.
Sparrowhawk, who was known affectionately as Laughing Boy or LB, was epileptic, autistic and had learning disabilities, and died after suffering an epileptic seizure.
An inquest jury ruled in October that neglect contributed to his death.
Ryan has told how she was "horrified" to find an abusive voicemail left on her work phone on April 29 from a woman who claimed to be a worker at Southern Health.
In the message, Ryan was labelled "vindictive" and a "nasty cow".
The full transcript of the voicemail...
"Good morning, hello, hi, this is a message for Dr Sara Ryan, I’ve been seeing on the media about your son, your poor son who died in the care of Southern Health.
"I work for Southern Health and I feel awful that you lost him, I’m so sorry that you have done, it’s tragic, and, I hope you find some closure after the report, the issue of the GM… CQC report today, but I do think you are being very vindictive. I think you are a vindictive cow.
"On TV all the time, slating the NHS Southern Health. With your intelligent background, you know, as much as much as anyone else knows, that Southern Health only took over those units in Oxfordshire recent, you know the recent months before your son died.
"You know, with your background, it takes a while to make changes in anywhere, and I think now you’ve just become a [inaudible] and you want some attention, but you are vindictive and you are unpleasant, and you are a nasty cow."
Ryan said in her online blog: "The call is vitriolic, nasty and beyond inappropriate. But it’s simply part of a set of improbably, inappropriate, nasty and worse responses we've endured since LB died.
"Evidence of a system in which defensiveness, bullying and family crushing flourishes."
She also told ITV: "I felt quite sick, I felt horrified and couldn't believe what I was hearing. We posted it online and the response we've had has been immediate. People are disgusted by it and shocked by the whole thing."
A Southern Health spokesman said it would carry out an internal investigation into the call, the Press Association reported.
He said: "We have been made aware of the phone message through social media, and the content is deeply concerning. The Trust cannot condone such behaviour and we take matters like this extremely seriously.
"We urge anyone with any information to get in contact with us so a full internal investigation can take place."
Shadow mental health minister Luciana Berger on Tuesday called for the chief executive of Southern Health to be sacked after the Care Quality Commission (CQC) report published last week found the trust was still failing to protect patients from risk of harm.
An independent investigation found in December that it had failed to investigate hundreds of deaths since 2011.
Berger said the CQC report suggested "very little" had been done to improve the performance of the trust.
Health Minister Alistair Burt admitted the report made for "disturbing reading" as he said the Government had not ruled out the possibility of an inquiry.