Roberts took part in Britain's Olympic Ambition 2012 programme in Beijing
Britain's wrestlers have seen their biggest home event axed in the wake of UK Sport's decision to cut funding in the build-up to the London Olympics.
A 68% cutback in January left British Wrestling with £680,000 and no option, it claimed, but to cancel the GB Cup.
The event would have seen Scott Gregory and Philip Roberts, who won medals at a Mediterranean tournament in March, competing against fellow Britons.
"We've become victims of our success," said GB wrestling chief Malcolm Morley.
"This competition was well supported in 2008, its inaugural year.
"It is not so much the staging of the event that has proved prohibitive, but costs associated with it.
"The funding cut was a hammer blow and cancelling the GB Cup is a big disappointment, but we see this as one step back to take quite a few steps forward in the long term."
British wrestling has enjoyed some success in recent months with Gregory's silver in the 55kg category and Roberts's 66kg bronze in Cyprus just two of five medals won.
At the Alexandre Medved Tournament in Belarus in March, Krasimir Krastanov won a silver medal in the 55kg to add to the bronze he picked up in a tournament in the Ukraine.
And Yana Stadnik took the bronze in the women's 48kg division.