SURREY, B.C. -- Sweeping raids across B.C.'s Lower Mainland resulted in one of the province's largest-ever drug seizures - with possible connections to the drug trade in Mexico.

For six months, officers from the Combined Forces Special Enforcement Unit (CFSEU) of British Columbia were monitoring potential drug traffickers, and on Jan. 8, observed what they believed was a significant drug transaction taking place in Surrey.

The suspects tried to flee but were eventually caught and the two men were arrested. That incident also led to six search warrants being executed across the Lower Mainland.

All up, officers say they seized about 38 kilograms of suspected heroin and 10 kilograms of suspected imitation Percocet, which are both believed to contain fentanyl.

That's in addition to 1.5 kilograms of suspected methamphetamine, $20,000 cash and three firearms.

The haul was put on display for the media Monday, including packages of drugs featuring skull imagery.

"These skulls on the bricks here obviously dictate El Chapo and the inference there that can be drawn by any reasonable person is that they’re associated in Mexico," Supt. Paul Dadwal said.

"We have no concrete evidence at this time. Our investigation is unfolding. That's one of the theories that we'll explore.”

It's considered one of the largest seizures in the history of the CFSEU, with a street value estimated to be $6.5 million.

But despite the significant haul, the two men arrested were released without charge.

Investigators are asking for anyone with information to come forward.