Indicted: Texan lawyer Mikal Watts and six co-defendants are charged with submitting more than 40,000 false claims for damages on behalf of fishermen

US lawyers bought themselves luxury cars after allegedly launching more than £1bn of fraudulent cases against BP, including claims on behalf of several dead people and a dog.

Texan lawyer Mikal Watts and six co-defendants were indicted by a federal grand jury on 95 counts of conspiracy, wire and mail fraud and identity theft relating to BP's 2010 oil spill.

They are charged with submitting more than 40,000 false claims for damages on behalf of fishermen, after the 2010 Deepwater Horizon explosion that killed 11 rig workers and triggered a huge oil spill.

'The defendants in this case are accused of exploiting a disaster relief programme set up to help those who were injured or suffered an economic loss as a result of the BP oil spill,' said US attorney Gregory Davis.

He alleges the defendants used the names, dates of birth and social security numbers of people who had not agreed to be represented, did not exist or were dead.

Watts' lawyers say he had paid 'case generators' to find genuine plaintiffs and believed that most of the £1.3billion in claims were genuine, adding that 'fraud was committed somewhere down the line by others'.

In one case, according to court documents, Watts made a claim for more than £30,000 on behalf of 'Lucy Lu', who was described as a deckhand on a commercial fishing vessel.

But grand jurors allege Lucy Lu was in fact a dog.

The aim was to extract cash from the Gulf Coast Claims Facility, which BP set up to compensate genuine victims of the spill.

Two of Watt's co-defendants allegedly paid a combined £6.6million to take part in the suit, as a form of investment.

As Watts and his colleagues hunted for new cases, fellow defendant Greg Warren allegedly bought himself a BMW 328i and a BMW X3.

Court papers suggest that Watts's brother David raised concerns that many of the cases were fraudulent.

The case will fuel claims that BP, which estimates its bill for the accident at £36.4billion, was unfairly treated due to the US culture of litigation and the fact that it is a British company.

BP is suing Watts but the case has been suspended while a criminal investigation continues.

The oil giant complained in 2013 that it was being hit with a barrage of 'fictitious' compensation claims. These included claims from strippers who said their business tailed off in the wake of the spill.

BP (up 0.1p to 382.5p) declined to comment and Watt's law firm Watts Guerra did not return calls.