“I approached Scottish Rugby and asked for a release from my contract under compassionate grounds.
“Effectively, the stress and the strain on my family, who are back in Australia away from me, proved too much to continue to go on and to do this role the way it should be.
“With the time back home in Australia over the summer, it was able to give me a lot more insight into the sacrifices that they’re making, on top of those that I make as well.
“We also had a change in circumstances where, unfortunately, my wife’s parents are unwell, so that means the family relocating in the 12-month plan that we had is not feasible anymore.
“I can’t be away from my family for that amount of time and do the job the way it should be done.”
Fukofuka says Scottish Rugby has been understanding of his decision – and that it had nothing to do with the governing body or its rugby programme.
“That is what made it so hard – and it’s everything to do with what my family are sacrificing and what I’m missing out on being at home and being a father and a husband,” he said.
“Being here in Scotland has been amazing, I’ve loved every minute of living here and have really appreciated the opportunity, but not having my family with me and being able to share those experiences with them has been really tough.
“Our boys are quite young and are missing out on that support when I’m not there.”
Scotland next face Canada in six weeks time and Fukofuka is backing “first-class individual” Butcher to succeed in the role.
Scottish Rugby performance director David Nucifora added: “Whilst we are disappointed to see him depart, we fully respect and understand the reasons why he has made this decision.
“During his time in the role, Sione showed great passion and commitment to the national team and the wider women’s programme at Scottish Rugby.”