The chair of the Environment Agency accepted a nearly £100 dinner from water company lobbyists just days before water bills were hiked by 40%.
Regulators and the Government have been accused of having a “chummy relationship” with water firms by the Liberal Democrats who uncovered details of the meeting.
The Environment Agency’s role is to investigate and punish the companies found to have illegally polluted waterways.
Liberal Democrat environment spokesman Tim Farron MP said: “This will rightly stink to the public. Government officials shouldn’t be accepting a penny from a disgraced industry which pollutes our rivers whilst hiking bills.
“This is a complete mess and further proof of a chummy relationship between water firms and the government.”
Chair of the Environment Agency Alan Lovell accepted a £96 dinner from Water UK, the industry body representing the country’s water firms, on June 20.
The following week, Water UK announced their members would be increasing water bills by 40%.
Within the same Freedom of Information Request, Mr Lovell also accepted a £200 dinner and hotel stay from Yorkshire Water, as well as a £60 dinner from Severn Trent Water.
Mr Farron said: “The water industry is getting away scot free whilst treating officials and regulators to swanky dinners. It is an absolute scandal.
“This industry is rotten to its core and needs to start from scratch, starting with a new regulator, a ban on bonuses and hospitality gifts, and above all else a complete reform of water companies so profit is no longer put ahead of the environment.”
The Liberal Democrats have called for a ban on the water industry treating government and regulators to expensive hospitality.
Ofwat officials have been treated to dinners at a high-end London private members club, funded by water companies.
An Environment Agency spokeswoman said: “All of these meetings were working meetings and all expenses were properly declared, as per the strict rules we have in place on gifts and hospitality.
“It is not unusual for the Environment Agency Chair to meet with industry leads to challenge them on their performance and outline the improvements that we as a regulator expect to see.”