Former All Blacks prop Carl Hayman has reportedly been convicted of domestic assault in France.

The 39-year-old was handed a four-month suspended prison sentence for domestic violence, according to the L'Equipe newspaper.

He was charged with several counts of violence against his wife between 2016 and 2018, including "a powerful slap" that required her to spend three days off work.

As well as physical violence Hayman was charged with psychological damage, nuisance calls and insults.

"It's inexcusable," Hayman reportedly told the Criminal Court at Pau.

Hayman admitted to having a serious alcohol problem at the end of his career, French media reported.

His lawyer, Christophe Arcaute, told the court: "He knows that he committed the irreparable.

"To recognise that he's an alcoholic, to admit his weaknesses in this particular environment, that doesn't happen.

"He is aware that the facts are serious. He is teetotal now."

Hayman has separated from his wife, former TVNZ reporter Natalie Crook.

He had spent the last few months dedicating himself to raising money for charity and was now planning to return to New Zealand.

Hayman had been the forwards coach at Pau until his sacking by the Top 14 side in January after an altercation with members of his squad.

Hayman played 45 tests before abruptly ending his New Zealand rugby career after the 2007 World Cup.

In all he played over 300 professional games for Otago, the Highlanders, Newcastle and Toulon, where he won three European titles.