Nearly 13,125ft (4,000m) beneath the surface of the Atlantic Ocean, salt corrosion and metal-eating bacteria have worn away parts of the liner's structure.
The team of divers found the hull near the officers' quarters on the starboard side of the ship has started to collapse, taking with it the vessel's luxurious stateroom accommodation, according to exploration company Caladan Oceanic.
Titanic historian Park Stephenson said the deterioration of the ship was "shocking", adding: "That whole deck hole on that side is collapsing, taking with it the staterooms, and the deterioration is going to continue advancing.
"Captain's bath tub is a favourite image among the Titanic enthusiasts and that's now gone."
The first ever 4K quality images of the ship were captured during the expedition and will be published alongside a documentary, which is being made by film company Atlantic Productions.
The footage will also make it possible to view the wreckage using interactive augmented reality and virtual reality technology.
Explorer Victor Vescovo, who is also chief executive of Caladan Oceanic, said he "wasn't quite prepared" for how large the wreckage is.
He said: "It was extraordinary to see it all, and the most amazing moment came when I was going along the side of the Titanic and the bright lights of the submersible reflected off a portal and came right back - it was like the ship was winking at me.
"It was amazing."
The Titanic is "going to continue to deteriorate over time" as part of a natural process, according to scientist Lori Johnson, who added that bacteria is acting like "a community working symbiotically to eat" the wreckage.
A total of five dives to the wreck, which lies around 370 miles south of Newfoundland in Canada, were made over eight days using a submergence vehicle.
The Titanic, built by Belfast's Harland and Wolff shipyard, sank after hitting an iceberg on her maiden voyage from Southampton to New York in 1912, resulting in the deaths of more than 1,500 people.