The seven United Road Transport Union (URTU) men arrested by police as part of a fraud investigation relating to the Driver CPC have had their bail extended until September.
All were arrested on suspicion of fraud by false representation in February as part of a police and Driving Standards Agency probe.
They include URTU general secretary Bob Monks, national officer Mel Thornton, and regional officers Lee Pimbley and Mike Billingham.
Their bail terms had originally been extended until 30 July, but a Greater Manchester Police spokesman says the men must now answer bail again on 6 September.
URTU says that it is “cooperating fully with the investigation”.
