Thames Water has been fined £20.3million - the largest penalty handed down to a water utility for an environmental disaster - for polluting the River Thames with 1.4billion litres of raw sewage.

Hundreds of fish and birds died over a two-year period when 'out of control' sewage treatment centres owned by Thames Water, sent 1.4billion litres of untreated water into rivers in the beautiful countryside of Oxfordshire, Buckinghamshire and Berkshire.

The fine, which is the largest in the firm's history, was delivered after tampons, condoms and sanitary towels were left floating between the banks of one of the world's most famous rivers and forced a crayfish fisherman to lay off his staff for three years.

Photo issued by the Environment Agency of sewage foam collecting at the Upper Thames Sailing Club

Picture issued by the Environment Agency of a condom in the River Thames downstream from Little Marlow

Dead fish in the Fawley Court Ditch downstream of Henley Sewage Treatment Works

Judge Francis Sheridan handed down a fine of £20,361,140 - the largest penalty for a water utility for an environmental disaster - at a sentencing hearing at Aylesbury Crown Court today.

Handing down the fine, which is ten times higher than the previous record penalty paid by Southern Water, Judge Sheridan said: 'This is a shocking and disgraceful state of affairs.'

He added: 'It should not be cheaper to offend than to take appropriate precautions.'

Thames Water has 21 days to pay.

The firm admitted 13 breaches of environmental laws over discharges from sewage treatment works in Aylesbury, Didcot, Henley and Little Marlow, and a pumping station at Littlemore.

It also pleaded guilty to a further charge on March 17 over a lesser discharge from an unmanned sewage treatment plant at Arborfield in Berkshire in September 2013.

The judge also took into account seven further incidents at sewage sites on the Thames in 2014.

Sewage foam collecting around boats at Bourne End Marina. Thames Water has been fined £20.3million - the largest penalty handed down to a water utility for an environmental disaster

Foam building up in the final settlement tank at Henley Sewage Treatment Works

At a hearing last week, the judge said he had to ensure the fine was 'sufficiently large that they (Thames) get the message'.

Thames's previous record fine for pollution was £1 million, paid in January 2016.

The sentencing followed a ruling in March 2016 that big commercial organisations which cause environmental pollution can be ordered to pay fines running into tens of millions of pounds.

According to the Environment Agency, which brought the Thames prosecution, the previous largest fine handed down to a water utility for an environmental disaster was given to Southern over an incident on Margate Beach in Kent in 2012.

Thames Water chief executive Steve Robertson outside Aylesbury Crown Court, where Thames Water was fined £20.3million

Pictured is the Thames Water sewage treatment works in Didcot, Oxfordshire

Richard Aylard, Thames Water, said outside the court: 'We have failed in our responsibility to the environment and that hurts both personally and professionally because we do care.

'We've also failed in our responsibility to our customers, who pay us to provide an essential public service all the time, every day and not just some of the time, and we apologise for all of those failings.

'But in the three years since the last of those incidents we have learnt our lesson - there have been sweeping, far-reaching changes across the waste water business.

10 LARGEST FINES BROUGHT BY THE ENVIRONMENT AGENCY The £20.3m fine handed to Thames Water is the largerst fine handed to a water utility for environmental pollution. It is 10 times larger than the previous stiffest penalty handed down by a court, a £2m fine that Southern Water was ordered to pay in December for polluting the beach at Margate in Kent during the Diamond Jubilee weekend in 2012. It follows a ruling in March last year that big commercial organisations which cause environmental pollution can be ordered to pay fines running into tens of millions of pounds. At that hearing, Lord Chief Justice Lord Thomas and two other Court of Appeal judges in London stressed that, in some cases, fines in excess of £100 million could be imposed as a 'necessary and proper consequence of the importance to be attached to environmental protection'. Here are the 10 largest fines handed down after prosecutions brought by the Environment Agency against water utilities: Thames Water, £20.3m, March 2017

Southern Water, £2m, December 2016

Yorkshire Water, £1.1m, April 2016

Thames Water, £1m, December 2016

United Utilities, £750,000, March 2015

United Utilities, £600,000, June 2016

Yorkshire Water, £600,000, January 2016

Southern Water, £500,000, November 2014

Severn Trent, £480,000, September 2015

Severn Trent, £426,000, July 2016 Source: Environment Agency Advertisement

'That has included more people, more and better systems and more investments, and that is beginning to pay off.

'Our performance has improved considerably and we're also doing a lot of work which we're proud of in partnership with environmental groups across our area, working to improve rivers and not just get them back to where they should be.'

He insisted customers will not face an increase in prices and added: 'This fine will be paid in full by shareholders only.'

Anne Brosnan, the Environment Agency's chief prosecutor, said: 'Thames Water was completely negligent to the environmental dangers created by the parlous state of its works.

'Our investigation revealed that we were dealing with a pattern of unprecedented pollution incidents which could have been avoided if Thames Water had been open and frank with the Environment Agency as required by water company industry protocol.'

The agency's chief executive Sir James Bevan added: 'This case sends a clear signal to the industry that safeguarding the environment is not an optional extra, it is an essential part of how all companies must now operate.'

Consumer groups and charities welcomed the fine.

Sir Tony Redmond, the London and South East chairman of the Consumer Council for Water, said: 'These were extremely serious and unacceptable failings by Thames Water which had a devastating impact on the natural environment.

'We believe a fine of this magnitude sends a very clear message to the company that it needs to take seriously its environmental responsibilities.

'Thames Water says it has learned lessons and we'll be watching closely to make sure it acts on these.'

Rose O'Neil, water policy manager at WWF, added: 'This ruling and fine is welcome and needs to focus the minds of all water companies and their shareholders as it is not an isolated issue.

'This case highlights the need for water companies to invest in solutions that manage the whole local catchment area such as green infrastructure and sustainable drainage systems.

'They simply can't continue treating our rivers as their dumping ground.'