Peter Ling’s wife told how her husband broke down two weeks before their wedding anniversary as he confessed his affair with a teacher.

Mr Ling, 50, a gardener from Wallington, is accused of murdering Coulsdon’s Lynda Casey in Banstead Woods on August 8 last year.

In a statement read to a jury at the Old Bailey, Deborah Ling said her husband looked like a “broken man” as he told her he had “lost it” when trying to split up with Mrs Casey.

The day before Mrs Casey’s death, Mrs Ling had confronted her husband after finding his Facebook status set to “interested in women and dating”. The next evening he had taken her out for dinner and acted emotionally.

Reading Mrs Ling’s statement, prosecutor John Coffey QC said: “[Mr Ling] said, ‘Something terrible has happened, I think I’ve done something awful’.

“He said he had been having an affair for two years with a tutor. He then went on to say, ‘I wanted to choose you’.

“He said I met [Mrs Casey] in Banstead Woods and told [Mrs Casey] I was going to be with [his wife]. He said [Mrs Casey] was going mad, I think he used the word hysterical.

“He said [Mrs Casey] had hit him and he had lost it. He said he had hit [Mrs Casey]. He said, ‘What if I killed her?’.

“I told Peter to go straight to the police.”

On August 11, Mrs Ling stayed at her mother’s house. When she returned home she found an answer machine message from Mr Ling saying she “meant the world to him” and that he had to make a decision about whether to confess of commit suicide.

Mr and Mrs Ling met in January 1984 in a Cheam nightclub when she was 23 and he was 25. They married in August 1986 but had no children and had tried IVF. In the last three years their marriage had been deteriorating.

In her statement Mrs Ling said earlier on the evening of August 11, Mr Ling had asked her to run away with him. She said: “Don’t be ridiculous.”