Mark Todd was once New Zealand's golden boy.

Now, the country's most successful equestrian has split with his wife of 24 years and upped sticks permanently to England.

Carolyn Todd stood by her husband through accusations in a British newspaper that he was dabbling in cocaine and casual relationships with other men.

The Sunday Mirror ran grainy pictures in 2000 of Todd allegedly snorting cocaine with a man - an episode he later called a "squalid tabloid set-up".

He appeared on Holmes but refused to deny the allegations, saying only that the question was "a curly one".

Yesterday, Carolyn Todd said the couple were legally separated and were selling the family farm in North Canterbury.

She has remained in New Zealand to tie up loose ends including the property sale, she said.

"It's mostly cattle on it now," she said. "All Mark's horses have gone to the sales."

The decision to split was made 18 months ago, she added.

Real estate agent Sue Woerlee, of Bayleys in Rangiora, said the Todds had made a "conclusive decision to sell". The asking price for the 24ha equestrian estate is $2.25 million.

The two-storey weatherboard homestead has five bedrooms plus a swimming pool and tennis court.

The Todds ran their horse bloodstock business from the property, 36km north of Christchurch.

It features 25 fenced paddocks and a world-class stable complex. There is also a two-bedroom staff cottage.

Todd retired from showjumping after the Sydney Olympics in 2000 but returned to represent New Zealand in the 2008 Beijing Olympics.

The couple have two children, Lauren, 22, and James, 17.