Kingston Crown Court heard that traces of DNA from Waheed Ali and Sadeer Saleem were found at an address in Alexandra Grove, Burley.
The court was told that, following the 7/7 bombings, it was identified as one of the locations where the explosives had been prepared.
A key for a Mitsubishi car like one belonging to Ali and Saleem's co-accused, Mohammed Shakil, is also said to have been discovered at the address.
Other work on the bombs was allegedly carried out at a property on Chapeltown Road.
Ali's fingerprints were found on a chest of drawers at that address, jurors heard.
Ali, 24, Saleem, 27, and Shakil, 31, all from Beeston, Leeds, deny conspiring with the four suicide bombers who murdered 52 people on the London transport network in the summer of 2005.
Prosecutor Neil Flewitt QC said the men's connections to the bomb factories completed a "compelling picture of their guilt".
Traces of Ali's DNA were found on a small Nike rucksack seized from Alexandra Grove in the aftermath of the bombings, the court heard.
The DNA of Saleem, who is asthmatic, was discovered on an inhaler. Further traces were recovered from a blood stain on a pair of martial arts trousers.
Jurors yesterday heard further details about a two-day trip which Ali, Saleem and Shakil made to London with 7/7 bombers Hasib Hussain and Jermaine Lindsay.
The prosecution claim the visit was a "hostile" reconnaissance of potential attack targets.
Mr Flewitt said the defendants' journey down the M1 from Leeds on the morning of December 16 2004 had been traced via mobile phone records. As reported in later editions of yesterday's YEP, one call was made to Leeds's Thomas Danby College, where Hussain was on a business studies course.
Attendance records show he was absent from his classes on that day.
The five men spent the night of December 16 at a £15-a-head hostel in Kings Cross.
Shakil's Mitsubishi Carisma car incurred a parking charge notice the following morning and a letter was sent to his address in Beeston.
The jury was told that on January 3 2005, Shakil reported that the car had been the victim of an arson attack outside his parents' home.
Mr Flewitt said: "One issue you may want to consider is whether it provided a convenient cover for disposing of the car and any secrets that may have been hidden within it."
The defendants all claim their trip to London was "entirely innocent".
Proceeding