A document revealing how a safety officer warned that the Titanic needed '50 per cent more lifeboats' but was suppressed from voicing his fears has emerged.
Civil servant Maurice Clarke inspected the liner for lifeboats and safety equipment five hours before she left on her doomed maiden voyage 100 years ago.
He made handwritten notes at the time in which he clearly stated the vessel did not have enough lifeboats.
But he wrote that if he made the recommendation official his job would be threatened as Titanic's owners had pressurised his bosses into giving the ship the all clear.
The revelation of a cover-up have come to light for the first time in a century after Mr Clarke's 'smoking gun' documents were made available for sale at auction.
They show he boarded the vessel at 8am on April 10, 1912 to carry out his checks before granting Titanic a certificate to allow her to carry emigrant passengers.
Under the heading 'boats', he acknowledged it was not possible to double the number of lifeboats from 20 to 40 to cover 'all hands' due to cost and extra manning.
But Mr Clarke, the emigration officer for the government's Board of Trade, wrote: "I suggest 50 per cent more."
He stated that an increase of 50 per cent would mean 30 lifeboats that would carry 1,767 people in an emergency.
He wrote: "This permits of all persons being transferred to another ship in one return, not 3.
"A sufficiency of boats would allay a panic."
But he added, tellingly: "To deviate...would leave me without support.
I might be shifted as suggest to me by owners if I enforced my views as to efficiency."
Incredibly, his notes also reveal that Titanic only had six life buoys on board, which equated to one per 370 people.
In the event, the Titanic left Southampton for New York with the legal minimum 20 lifeboats that had a capacity for 1,178 people.
Only 706 passengers and crew made it into the boats and 1,522 people died after the Titanic struck an iceberg and sank on April 15, 1912.
Despite his concerns, Mr Clarke towed the party line when he later gave evidence at the official inquiry into the disaster and did not repeat his views.
When asked whether Titanic was in a proper order to go to sea as an emigrant ship he replied: "Undoubtedly."
His documents are to be sold at auction by Henry Aldridge and Son of Devizes, Wilts.
Andrew Aldridge said: "This has to be the most controversial document relating to the Titanic that has emerged in the last 100 years.
"This is clear evidence that a company, namely White Star Line, had sufficient influence to gag a government employee.
"Maurice Clarke felt the number of lifeboats on Titanic was inadequate and he wanted 50 per cent more.
"But he was told, or he was under the impression, that he would be moved from his position if he proceeded with this course of action.
"He felt he could not go go public or make his views known to the powers that be because the owners had made it clear that he wasn't allowed to.
"Had he done so, in his words he would have been shifted, which I think would mean moved position or demoted.
"This statement implies that the Board of Trade officials in charge of clearing Titanic had been pressurised by White Star Line with regard to the subject of insufficient lifeboats.
"This is a fact that has never been known before. It was a judgement which had calamitous results only five days later when Titanic sunk.
"If his recommendations for 30 lifeboats been accepted then potentially more than 1,000 out of the 1,500 people who died could have been saved.
"In hindsight, there was a very strong case to bring charges of corporate manslaughter against White Star Line over the disaster.
"If that had happened, then this document would have been the smoking-gun piece of evidence that would have helped convict them.
"Yet when Maurice Clarke gave his evidence to the official enquiry he played it with a very straight bat and towed the party line."
The documents were obtained by a solicitor more than 50 years ago and it is his son who is now selling them with a pre-sale estimate of 30,000 pounds.
They also include a typed statement from Mr Clarke to the Board of Trade in response to receiving a list of questions he was likely to be asked at the enquiry.
The auction takes place on November 24 in Devizes.