The man accused of murdering children's author Helen Bailey who had a home in Broadstairs became increasingly 'frantic' the days after reporting her missing to the police, a court heard.

Ian Stewart, 56, 'became frantic trying to help the police,' after reporting her missing from their £1.5m home at Royston, Hertfordshire, on Friday, April 15, last year.

Stewart's son Jamie took to the stand to give evidence against his father at the fifth day of his trial for murder, at St Albans Crown Court, Hertfordshire.

Prosecutors claim Stewart probably suffocated Mrs Bailey, 51, and then dumped her body in a cesspit after drugging her with sleeping medication he had been prescribed.

The body of her beloved daschund Boris was also found in the cesspit.

The Crown claims he murdered her to gain her fortune worth £4 million.

Jamie, who lived with his brother Oliver at the couple's home, told how he had seen his father on the evening of April 11 when he is alleged to have murdered Helen.

Mr Stewart, 24, said he had a bowls competition on the day Helen was allegedly murdered and his father came to watch.

The father then picked up a Chinese takeaway on the way home and the pair sat in the living room of the house watching television while they ate it.

He said he assumed Helen was home at the time as her white jeep was outside, but didn't see her himself.

The following day he said it was "unusual" that Boris the dog had not run up to him when he came from work like he always would.

Mr Stewart said: "I asked my dad if Helen and the dog had gone off for a walk because I had not seen them in the house.

"He said at that point Helen had gone to Broadstairs to get some time to herself and she had left a note saying not to contact her."

He continued: "He told me he thought he had thrown it (the note) out with the rubbish."

Mr Stewart said his father throughout the week "got visibly more stressed out" and spent more time with Jamie and Oliver.

He said his father told him on Friday, April 15, he had reported Helen as missing as no one had heard from her since Monday.

He said: "Through the week he got more and more stressed. The following weekend he became frantic trying to help the police find her.

"Dad asked whether Helen had been in contact with me - she had not."

The court also heard Stewart pushed for the sale of a property she owned to go through and tried to register as power of attorney after he allegedly murdered her.

The court heard Helen was in the process of selling her £185,000 property in Gateshead, Newcastle, and had been visiting a solicitors in the days before her alleged murder.

"He said at that point Helen had gone to Broadstairs to get some time to herself and she had left a note saying not to contact her" - Jamie Stewart

Stewart was later arrested on Monday, July 11, and released the following day and was in a hotel with his sons while police were searching the home they shared.

Mr Stewart said: "I think he was very stressed out and concerned about what was going on and why it was all going on as well."

Prosecutor Stuart Trimmer QC asked whether Mr Stewart knew two men by the name of Joe and Nick, and whether his father had suggested they had "taken" Helen away. He replied "no".

Mr Trimmer said: "Did he ever mention to you that he was tasked to find Helen Bailey's phone and that he was told to take that phone to Broadstairs?" Mr Stewart said no.

Stewart, of Royston, Hertfordshire, is on trial for the murder of Helen, one count of fraud, one count of preventing lawful burial, and three counts of perverting the course of justice.

He denies the charges.