Marc Grosjean attacked his wife after using her Sat Nav to discover she was having an affair, pictured outside Westminster Magistrates Court today

A former Credit Suisse director punched his wife and tried to tear off her wedding ring after he used her Sat Nav to find out she was having an affair, a court heard.

Frenchman Marc Grosjean, 43, hit Artemis Berberi in the face and injured her hand in the struggle at their London home which was witnessed by their son.

Grosjean had gone through Ms Berberi's phone and Sat Nav to confirm his suspicions that she was seeing another man, Westminster Magistrates Court heard.

The former banker was found guilty of assault and sentenced today to eight weeks jail suspended for two years for the sake of his son.

District Judge Paul Goldspring noted that Grosjean had shown 'controlling behaviour' by monitoring his wife's movements before the 2015 attack.

‘That was evidenced by your analysis of the sat-nav to find out where she had been,' he said.

‘This was in my view serious within the context of the common assault because it was in a domestic setting, some of it in the presence of your child and the level of violence was significant.

‘You used your hand when it was clenched to hit your partner twice. In doing so you did cause injury, which was reddening and bruising to her cheek.

‘Ms Berberi also had to endure a retelling of her sexual infidelity in front of a strange court with strange people.'

The court heard Grosjean was stressed at the time of the attack because of the strain of starting his own Market Engineering

Abbas Lakha, in defence, said setting up his own business had taken 'an enormous toll.'

Grosjean had gone through Ms Berberi's phone and Sat Nav (stock) to confirm his suspicions that she was seeing another man, Westminster Magistrates Court heard

'This has been an extremely stressful time for him. It has taken an enormous amount out of him, as well as the matrimonial proceedings.

'In 2015, around the time of these events, he was in the process of setting up his own business.

Mr Lakha added: 'He has always been a hard worker and someone who has provided for his family.

'His work, by definition, involved enormous risk and, by definition, to his family's well-being and financial security.

'His then-partner, the complainant, was undoubtedly in an affair behind his back. At the time, she made a total denial.'

Judge Goldspring found Grosjean was a 'good and loving father' apart from the 24 hours when he lost control.

'But your behaviour in that 24-hour period was nothing short of shocking. You used the back of your hand to strike your partner to the face,' he said.

'You were frustrated that the relationship was ending. But you are an intelligent 43-year-old man and should know that violence is never the way to deal with frustration.

'What saves you is nothing to do with you. It is to do with the welfare of your son, particularly when you are his sole carer. It is that saves you immediate custodial sentence.'

Grosjean was fined a total of £900, ordered to complete 200 hours of unpaid work and told to take part in a domestic abuse intervention programme, for 20 days.

Responding to Mr Lakha's request for six months to pay, the magistrate noted Grosjean had 'paid for very expensive QC'.

He added: 'I would ask people on benefits to pay quicker than that.'

Grosjean, who lives in Paddington, was found guilty of one count of assault by beating and one count of common assault.

A restraining order preventing him from contacting Ms Berberi was also made.