The sons of Diane Stewart have told of the moment they learnt their mother had died at home in Bassingbourn - telling the court, where their father is on trial for her murder, that he was "in tears".

Ian Stewart, 61, is on trial accused of the murder of 47-year-old Diane in 2010 - six years before he killed Royston author Helen Bailey and dumped her body and that of her dog Boris in a cesspit under their home.

Both of the Stewart boys were out of the family home at the time of Diane's death - Oliver, then 15, was at school and brother Jamie, who was 18, was taking his driving test.

Prosecutors say Stewart - who is originally from Letchworth - was initially able to "fool medical professionals by suggesting that Diane had died in the course of an epileptic fit", but brain tests later indicated it was likely her breathing was restricted from an "outside source".

Oliver Stewart was brought home from school by a neighbour. He saw ambulances outside the house, he said, and initially thought, "Oh, Dad's going to have another spell in hospital," as he had the rare long-term condition myasthenia gravis, which he described as "muscle weakness".

Oliver said someone from either the police or ambulance service told him his mother was dead. Wiping tears from his eyes, he told the jury he identified her body.

"She had foam coming out of her mouth," he said, adding he gave his mother "one last kiss".

Asked by defence barrister Amjad Malik QC how his father was at that point, Oliver replied: "In bits."

Oliver said he was given information from the pathologist about how his mother died at a later date. "I knew she was epileptic, I had seen the foam in her mouth, it added up," he said.

Oliver described the relationship between his parents as "loving, caring, kind, family-orientated".

The couple's older son Jamie, who was 18 at the time, told jurors he was taking his driving test on the morning his mother died.

"My driving instructor had driven us back from Cambridge. Then, when we pulled into our street, there were three ambulances outside our house," he said.

Jamie said his father was "in tears and very upset and I think the neighbour and paramedics were trying to console him".

Jamie said he knew his mother was epileptic and took two tablets every morning, but had not seen her have a fit "in my lifetime".

He said he remembered there were "raised voices" between his mother and father when he was at home on study leave for A-levels the week his mother died.

Questioned by Mr Malik, Jamie said he "couldn't hear what was being spoken about".

He said he had seen his parents argue over the years but it "wasn't a regular thing".

Asked to describe how his father was at the funeral, Jamie replied: "Devastated."

Mrs Stewart met her future husband while both were students at Salford University in the 1980s, the defendant's brother-in-law Philip Bellamy-Lee said.

The pair moved to Cambridge, with Mrs Stewart working for DHL, then for a "company that provided meat products to McDonald's", and then as a school secretary in Bassingbourn, Mr Bellamy-Lee, whose wife Wendy Bellamy-Lee is Mrs Stewart's sister, said.

He said his wife was "very close" to her sibling and "wanted to go to Bassingbourn" when she learned of her death.

He added: "She wanted to go there as she wanted to understand more about what happened, but she wanted to make sure the boys were cared for as well.

"At that time, Ian didn't want her presence so she accepted that. She still wanted to go as soon as possible...but at that time Ian was reluctant."

Mr Bellamy-Lee said his wife "wanted to talk to Ian - and tried to talk to Ian on numerous occasions - to try to understand what happened and he simply wouldn't talk to her."

Stewart is serving a 34-year term for the murder of Helen Bailey, which he was convicted of in 2017 after an eight-week trial.

Stewart denies the murder of his wife. The current trial, which started on Monday and is expected to last four weeks, continues.