Test showed Christian had high levels of salt in his system

Angela Gay, from Halesowen in Birmingham, said three-year-old Christian Blewitt was not responsive to cuddles and did not eat properly.

He died in 2002 and tests showed a high level of salt in his body and that he had suffered a brain haemorrhage.

Angela and husband Ian, 39, deny charges of manslaughter and cruelty.

It is alleged they forced the youngster to eat "a significant" amount of salt as a punishment.

There was just something about his behaviour that wasn't normal. I was worried that he was unwell Angela Gay

The prosecution also claim they handled him "inappropriately" by shaking him, or banging his head against a mattress.

The couple, who were caring for Christian and his two younger siblings as part of a 13-week trial, were convicted of manslaughter in 2005 but won a retrial on appeal.

Christian collapsed at their former home in Bromsgrove, Worcestershire, on 8 December and died four days later in hospital.

But 40-year-old Mrs Gay told a jury at Nottingham Crown Court that he began to act strangely around her in the four days prior to his admission to hospital.

She said he often became quiet when his younger brother was not around but would "come round" when she paid him more attention.

Ian and Angela Gay have always denied poisoning Christian

She added that he had also not been sleeping very well and the day before the toddler was found collapsed, she tried to interact with him but he rejected her three times and even bit and kicked her.

"I was worried about Christian's behaviour," she said.

"There was just something about his behaviour that wasn't normal. I was worried that he was unwell.

"I did try talking to him but I never got anything back that said something's hurting, or whatever. He just didn't seem himself."

She told the court that she did not punish him but her husband did talk to him and initiate some "calm down time" where Christian was taken upstairs alone.

She said Christian, who was generally "a good eater" did not finish any of his meals and was unusually quiet and tired throughout the day.

The trial was adjourned to Thursday.