In the letter BISFed claimed that the existing tests "do not provide guarantees" that all balls used in tournaments allow for a fair competition.

At BISFed’s General Assembly in 2014, a motion was passed authorising the governing body to find a solution to the problem.

BISFed therefore tasked Loughborough University to conduct a two-stage research project and to advise on a solution.

In stage one, the University recommended that BISFed should introduce a new test - the ‘roll’ test - which determines the minimum distance a boccia ball must be capable of rolling in order to be accepted for competition play.

The letter invites manufacturers to participate in stage two - the design of the new roll test - by submitting a set of boccia balls.

This must consist of six reds, six blues and one white jack.

The issue is an interesting one for the sport with boccia preparing for September's Rio 2016 Paralympic Games.

London 2012 gold medallist Maciel de Sousa Santos warmed up for his individual BC2 title defence at his home Games in Brazil by earning victory at the BISFed World Open in Póvoa de Varzim.

The Brazilian ended the challenge of Portuguese home favourite Fernando Ferreira by winning 7-3 in their quarter-final meeting, before easing to a 15-0 win over Britain’s Josh Rowe to book his place in the gold medal clash.

Dutch player Bernd Meints gave Santos a strong test in the final but the Brazilian ultimately came through to secure a 5-4 win.