STAFF from the Gravesend headquarters of the Port of London Authority (PLA) led the rescue mission to save the Thames Whale.

The 18ft northern bottle-nosed whale, thought to be the first whale sighted in the Thames since 1913, was spotted by a patrol from the Gravesend PLA on Thursday lunchtime, near Dagenham.

Crews tracked the four-tonne mammal to Battersea on Friday, before deciding to launch a rescue mission on Saturday, after hopes she would make her own way out to sea faded.

PLA spokesman Martin Garside took part in the rescue effort, which is thought to have cost £100,000.

He said: "The consensus was for the whale to have come up the Thames in the first place, it was likely to have already been ill or injured.

"We gathered together a group of leading whale and marine mammal experts, along with the salvage craft from our headquarters in Gravesend and tried to save it."

The whale was in shallow waters by Battersea Bridge when it was winched onto the PLA craft using a sling at around 4pm on Saturday.

The distressed animal was then laid onto an inflatable raft and was given antibiotics by a vet as it was carried upstream.

Sadly, the whale, since revealed to be an adolescent female, began to convulse and died on the vessel as it passed Cliffe at around 7pm.

Her body was brought back approximately five miles to Gravesend and laid on a PLA jetty, where an autopsy was carried out on Sunday night.

The results of the autopsy, conducted by the London Zoological Society, are expected to be released this week.

Mr Garside said: "This whale was hundreds of miles from home, it should have been somewhere in the Atlantic where the normal depth is 1,000m. When there's a low tide at Battersea the Thames is only 3m deep.

"It was desperately sad but it was incredible to see all the support as we tried to help her."