A shipwreck with enough explosives to cause a "catastrophic" tidal wave up the Thames is deteriorating faster than feared, experts have said.

The SS Richard Montgomery sank in the Thames Estuary in August 1944 with 1,400 tonnes of explosives still inside.

Plans to remove the three masts, which can be seen above the water’s surface, have now been brought forward after a new assessment discovered the corrosion.

Experts suggest the corrosion is plaguing the masts worse-than-expected and could trigger a potentially "catastrophic" blast.

Southend Labour councillor Lydia Hyde has warned that things had reached a point where it was safer to act.

She said: "There was an assessment in the summer, and then there was a more detailed one in November, to basically go and look at the condition of the masts.

"The concern is that corrosion means they catastrophically fail, their structural integrity goes, the mast falls down and then lands on the wreck, and then that could set off an explosion.

"Following the dive, they’ve assessed it and they’ve gone 'actually, no, we need to bring this forward because the corrosion was more than expected'."