"There's not a lot there at the moment. We didn't raise hundreds of thousands of dollars in New Zealand."
"That's why we have the dinner in London. There's much more support for Jonah's legacy up there and people want to help.
"We have to use special events such as there to create the corpus that can carry them through to adulthood."
He said it meant trustees had to be careful about making payments from the fund because the current balance wasn't enough itself to generate the money the boys would need in their lives.
"There is a corpus but it's not big enough. You want to create a corpus that is large enough to be self-sustaining. That's what we're trying to do."
He said he believed that rugby players were seen as "just men" in New Zealand, whereas other nations with larger populations raised them higher. "When you have a small country it's hard to idolise someone. The respect for Jonah is a lot more tangible in Europe than it is in New Zealand."
Jones said he had known Lomu for years, and that the rugby star had also become a part of his children's lives. Like the other trustees, no fees were charged for extensive professional services.
Jones said: "We don't charge fees. We want to retain every dollar we get for the boys."
There were more than 600 people registered for the London dinner and it had attracted major sponsors included NatWest bank and the Telegraph newspaper.
The dinner is being marketed under Lomu's image with tickets selling up to $8300 for a table of 10 people.
Promotional material for the dinner stated: "The Jonah Lomu Memorial Dinner will not only celebrate his life and outstanding career but will also raise funds for his two young sons, Brayley and Dhyreille, that he left behind."
Jones said there had been Lomu memorabilia gifted to the trust which would be auctioned, including his 1995 Rugby World Cup squad cap and his 50th test jersey. There were also portraits contributed by a number of artists and a bronze bust of the player.
The memorable Irish Examiner front page was also hoped to generate funds for the trust after the newspaper donated the copyright.
A further auction would be held in New Zealand for items with a particular local interest, such as number plates which referenced Lomu.
Nadene Lomu, the star's wife and mother of the boys, issued a press release yesterday to give "heartfelt thanks and appreciation to all of those people who have supported our boys and myself since Jonah's death a year ago".
"There have been many of you who have helped us through the toughest year of our lives.
"The boys (Brayley and Dhyreille, seven and six) are doing as well as you could expect but they miss their daddy hugely and we talk of him every day."