Nairobi, June 7 -- Five mattress manufacturers suspected of being involved in cartel activity that inflated product prices unknowingly exposed their collusion after jointly seeking a pre-emptive court injunction to block a planned raid on their premises, heightening the watchdog's fears of secret cooperation and price fixing.

On March 30, the manufacturers moved to court seeking orders to stop an impending raid by the Competition Authority of Kenya (CAK), citing violations of their rights to privacy, property, fair administrative action and data protection.

However, the petitioners quickly withdrew the suit the following day after realising that fatal mistake of filing their suit jointly, which inadvertently strengthened the competition...