The former EastEnders star turned documentary maker was planning to take part in the deep diving mission last year for a programme to mark the 110th anniversary of the sinking of the ill-fated liner.

But an expert production company behind the documentary decided it was too risky to board the submersible after carrying out its own checks.

Kemp's agent, InterTalent chairman Jonathan Shalit, said the production company deemed the vessel to be unsafe "on every level".

On Thursday, the US Coast Guard said OceanGate's Titan submersible had imploded during a trip to the Titanic wreck, killing all five people onboard.

"We were told 'it is unsafe, we are not going' - that was a year ago," Mr Shalit said.

"It is deeply sad for the families who have suffered such a terrible loss."

He added: "I am relieved that Ross did not participate but I am obviously reassured by the professionalism of those companies we were working with that they didn't suggest that he go on the submarine.

"The lesson to be learnt is do your checks thoroughly. By good fortune for us, the checks had been done thoroughly."

On Thursday, Rear Admiral John Mauger - who led the search for the missing submersible - confirmed a remotely-operated vehicle had discovered the nose cone of the lost submersible about 487m (1,600ft) from the bow of the Titanic on the seafloor.

Further debris was found nearby, with Rear Admiral Mauger adding: "In consultation with experts from within unified command, the debris is consistent with the catastrophic loss of the pressure chamber."

British billionaire Hamish Harding, UK-Pakistani businessman Shahzada Dawood, his 19-year-old son Suleman Dawood, OceanGate founder Stockton Rush and French national Paul-Henri Nargeolet were on board.

Read more:
What happened to the Titan
Billionaire was offered last minute-price tickets for doomed voyage
Five men on board described as 'true explorers' - here are their stories

Veteran explorer Josh Gates, who hosts Expedition Unknown on Discovery+, also revealed he turned down the chance to film on the doomed Titan submersible.

He tweeted that he had rejected the opportunity to film in 2021 because the vessel "did not perform well" during a test dive.

He wrote: "Ultimately, I walked away from a huge opportunity to film Titanic due to my safety concerns with the OceanGate platform.

"There's more to the history and design of Titan that has not been made public - much of it concerning."

On Friday, one of OceanGate's co-founder's, Guillermo Sohnlein, hit back at comments made by Titanic film director and ocean explorer James Cameron about the Titan submersible's safety.

Mr Sohnlein told Times Radio there had been a "rigorous test programme".

He said: "I was involved in the early phases of the overall development programme during our predecessor subs to Titan, and I know from firsthand experience that we were extremely committed to safety, and risk mitigation was a key part of the company culture."