ON Sunday night, two-year-old Christy Ruddell was seen playing football with his mother in the back garden.

A few hours later, he was dead and Melanie Ruddell had been arrested on suspicion of murder.

Police are now faced with working out how this seemingly happy family scene descended into tragedy.

Superintendent Rob Coulson, of Durham Police, said: “While I am not in a position to comment on any medical issues, what I can say is she is described by family and friends as a doting mother.

“She had difficulty leaving Christy with babysitters to go out.

“Christy was a fit, healthy, vivacious little boy who loved his football. On the day before his death, his mother was playing football with him in his uncle’s garden.

“What we really need to understand and establish is how can she go from (being) a doting mother to these tragic circumstances.

What could cause that?”

Mrs Ruddell married Christy’s father, Alan, at Hardwick Hall Hotel, near Sedgefield, County Durham, three years ago.

At first, it seemed things were going well. She worked as a welder, he at the Caterpillar factory, in nearby Peterlee, and the couple were keen to start a family.

A neighbour said: “She had a very bubbly personality. Melanie wanted children.

“Having a child was so important to her. They were overjoyed when they had a baby.”

The couple named their son Christy after Irish folk singer Christy Moore.

Mr Ruddell, a music fan who used to sing and play guitar at their village’s Castle Eden Inn, wrote a message on the singer’s website, telling him they had named their son after him. The singer replied, sending his wishes.

However, things started to turn sour. Both husband and wife lost their jobs and, although they both found alternative work, they separated about six months ago.

Neighbour Joanna Cooper, 42, said: “They had a feisty relationship and were frequently arguing.

It didn’t come as a great surprise when they separated.”

For support, Mrs Ruddell turned to her family – father John Close, brothers John and Neil and sister Julie Stout.

She moved in with Neil, a decorated war hero, in West Rainton, near Durham City, housesitting for him while he was overseas on tour.

Supt Coulson said: “There were issues around her health at the time. Following concerns (for her wellbeing) he had taken her in.

“We know that she was going through a divorce from her husband which has been quite traumatic and upsetting for her.

“We know that her family has been offering her support through that, which is the reason why she was stopping at her brother’s.”

It is thought Cpl Close returned home from leave only a week before Christy’s death.