A damaged cargo ship carrying 20,000 tonnes of 'potentially explosive' ammonium nitrate docked at Great Yarmouth without knowing that 300 tonnes of its load was already contaminated by seawater.

The MV Ruby vessel had arrived at Peel Ports' outer harbour in the town in the early hours of the morning of October 28 being pulled by tug boats.

Fears were raised when it was revealed that MV Ruby was carrying more than seven times the amount of ammonium nitrate involved in a Beirut blast which killed 218 people and injured a further 7,000.

Earlier this week, this paper revealed that she had dumped some of her load into the sea just 12 miles off the shores of Great Yarmouth before returning to the port.

Now the Maritime and Coastguard Agency (MCA) has admitted 300 tonnes of the 20,000 tonne load has become contaminated by seawater  - leading to it being dumped out to sea.

It was also revealed that non-essential port operations were halted to ensure the giant vessel complied with strict regulations.

Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth (Image: Luke Martin Photography) An MCA spokeswoman said: "During the transhipment of her cargo at Great Yarmouth, seawater and a small amount of hydrocarbons were found to have entered the forward-most hold of the MV Ruby.

"This is likely to have resulted from the grounding incident several weeks ago."

Before her arrival in Great Yarmouth on October 28, she had been anchored about 11 miles off the coast of Margate in Kent while awaiting repairs to her hull and propeller, which were damaged in bad weather.

The Maltese-registered boat had initially set off from the northern Russian port of Kandalaksha in July and was supposed to be taking her cargo to Africa before becoming damaged.

Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth (Image: Luke Martin Photography) The port had previously announced in a statement that it adhered to all of the UK's safety regulations as well as international maritime standards.

And the MCA still insists that the contaminated ammonium nitrate was not a risk to the people of Norfolk.

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The spokeswoman for the MCA added: "The Port of Great Yarmouth has the capability to handle hazardous materials, and the discharge and transhipment of such materials and cargo is common practice in both bag and bulk format.

"The MCA, Norfolk Resilience Forum, HSE and the Port worked together to mitigate any risk to local residents, including providing support and guidance on ammonium nitrate, halting all non-essential port operations and regular site checks to ensure compliance.

"The MCA and its partners have worked together to continually monitor the situation with the MV Ruby, including working to understand changing risks."

Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth Luke Martin Photography captures the Mv Ruby cargo ship arriving at Great Yarmouth (Image: Luke Martin Photography)