Rennie believed the Hamilton house, which he and his wife bought in February, was targeted by professionals who knew the family would be at the game. He said Sonny Bill Williams' home was burgled a couple of months ago during a Chiefs game, "so it's a hell of a coincidence, isn't it?"
He said the thieves used a crowbar to get in and take the safe, which was hidden and bolted to the floor. It also held foreign currency and son Matthew's university graduation certificate. The offenders also took a laptop.
Rennie said all the couple wanted back was the jewellery. Much of it was distinctive and one-off items made for his wife.
The couple had beefed up security at the house, including fitting an alarm sensor in the master bedroom and extra spotlights.
* Anyone with information is urged to call Hamilton police on (07) 858-6200 or call Crimestoppers anonymously on 0800-555-111.