In each of the clips, a person emerges from the driver’s side of the vehicle and approaches a building at the entrance to the depot, where they appear to have a brief exchange before barriers to the site are lifted to allow the lorry access.
It is estimated the total value of the items stolen, including the trailers and the Guinness, was about £205,000.
The trailers were found in Skelmersdale, Lancashire, last week.
One was left in the Hall Lane area shortly after 03:05 BST on Tuesday.
The second was dumped in the Gillibrands Road area shortly after 12:00 the next day.
Det Sgt Gary McClatchey said: “We will not settle for anything less than the full recovery of the near 900 stolen Guinness kegs and the locating of the offenders behind this brazen heist.
“As our investigation continues, we are now looking to identify the two men captured in the CCTV footage as we believe they hold vital information.
“I’d urge anyone who recognises these men [to] contact us so that we can progress with our investigation and I would also strongly encourage the men in the footage to please come forward.”
He continued: “As we have previously stated, these kegs are stolen goods that are looking to be sold on by criminals.
“So we are continuing to urge anyone who is approached by any prospective Guinness sellers to remain cautious and, as always, report any suspicions to police.”