Guptill was part of the T20 World Cup squad in Australia but did not play during the tournament with Finn Allen preferred at the top of the order and was left out altogether for the ongoing series against India.

"Playing for my country has been a massive honour, and I'm grateful to everyone within the Blackcaps and NZC for their support," Guptill said. "But, equally, I'm realistic enough to understand the need to consider my options in the current circumstances.

"With this release, I'm still available for New Zealand, I have the chance to explore other opportunities, and I also get to spend more time with my family - which is important."

It's understood that he could be in the frame for a BBL stint as a replacement player with at least two clubs looking for reinforcements ahead of the season.

"We understand Martin's position," NZC chief executive David White said . "He's been a fantastic batsman for us for a long period of time, and we certainly don't wish to stand in his way as he explores other opportunities.

"Martin's been a giant of the white ball game, a committed and well-respected member of the Blackcaps, and has earned the right to play out his career on his own terms. He leaves his contract with our best wishes."

Guptill's move follows that of Boult who relinquished his central contract earlier this year. He, too, was part of the T20 World Cup squad but has not been picked to face India. He has an upcoming deal with Melbourne Stars in the BBL before heading to the ILT20 with MI Emirates.

"Players such as Martin, Trent and Colin, with long and successful international track-records, inevitably end up with alternative playing options at this stage of their careers, and we respect that," he said. "It's just part of the natural ebb and flow of individual careers within team sport."