"Sugar Boy" Malinga, the World Boxing Council champion who will defend his title on the same bill, travelled from South Africa to be present and Italy's Vincenzo Nardiello came from Rome, but Benn was conspicuous by his absence.
The former WBC holder preferred to remain at his Jersey home as the countdown began for a fight which the promoter Frank Warren says is costing "many millions".
By coincidence, Collins will be training in Jersey for a third defence of the crown he captured from Chris Eubank 14 months ago. "I'm heading for Jersey next week, so I suppose he's packing his bags to get out before I arrive." Collins said. "I think by him not showing up, he's bottled it."
Benn's manager, Peter DeFreitas, was left to do the explaining. "With nine out of 10 boxers there would be no problem, but Nigel is Nigel. But what more can I do than notify him of the conference? He wanted seven days' notice, but I was only able to give him four. I will just have to ride the storm."
When Collins and Benn previously met to thrash out the details of a fight which Warren hopes will be worth pounds 2m from gate receipts alone, everything was conducted on a friendly basis. But now contracts have been signed it will all be different.
Collins, whose mental fortitude matched his physical strength in his two fights with Eubank said: "This is now business, and when it's business with me I am no longer your friend, probably your worst nightmare. I just hope he's going to turn up on 6 July."
Benn lost his WBC crown to Malinga in Newcastle in March, and Collins observed: "Taking nothing away from Sugar Boy, but I'd have knocked out Benn on the night. The real Nigel Benn did not show up.
"But I know he's going to come back, he's got his pride, he wants to win big time, but I want him to be at his best just like Eubank was."
Benn has a great record of winning as a challenger and DeFreitas added: "I am happy that Nigel is going as a challenger. He won his two world titles in America and Rome and fighting in Britain will be a bonus".Reuse content