This is the heartwarming moment a nine-year-old autistic boy broke down in tears after his mother brought him his first McDonald's since the start of lockdown.

Wati Rahim filmed herself showing her son Adam Bin Mohammad Irwan, nine, the McDonald's takeout Happy Meal on May 18.

The fast food giant reopened on May 10 in Singapore after weeks of closure due to the Covid-19 coronavirus pandemic.

The video begins with Wati sat in her car outside the family home.

'Hello guys. I'm getting McDonald's. It's a surprise!' she says.

Wati brings the food into the house and leads Adam into the kitchen where the food is spread out on the table.

At the outset, Adam thinks his mum is playing a prank.

'I thought you wanted to scare me,' he said, before giving his mum a hug, who is quick to reassure him.

'I didn't want to scare you! I wanted to surprised you. Look, what is it?' she said

'McDonald's,' he said.

Adam is then filmed eating some chicken nuggets. At one point he puts one of the nuggets up to his face as if to hug it.

He is heard thanking his mother through tears, delighted to see his favourite meal and overcome by the situation.

Wati added that McNuggets with fries and ice cream was Adam's favourite meal.

She also said that her son has sensory sensitivity and mild autism that caused his 'overreaction.'