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, the largest ship afloat at the time of her maiden voyage, did not have enough lifeboats, The Telegraph reported.
However, he wrote that if he made the recommendation official his job would be threatened as Titanic's owners had pressured his superiors into giving the ill-fated ship the all clear.
The revelation of a cover-up has come to light for the first time in a century after 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.
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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.
"This permits of all persons being transferred to another ship in one return, not 3," he wrote.
"A sufficiency of boats would allay a panic," he said.
However, he added, "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".
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, Clarke toed the company 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 on November 24 by Henry Aldridge and Son of Devizes, Wilts.
"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," Andrew Aldridge said.