The Environment Agency investigated the huge fly-tip off Hulbert Road on the outskirts of Havant after it was discovered in September last year.
The News revealed the waste had been dumped - discovered after a fire - with EA investigators appealing for help to identify the culprits.
Now the agency has said criminal proceedings are being considered against five men.
A spokesman said: 'Eighteen statements have been taken.
'Nine people have been interviewed under caution. A case file now will now go forward for the consideration of proceedings against five men connected to four different waste companies.
'One householder, one shop owner and two tradesmen have been given written warnings about their failure to comply with their duty of care in respect of waste disposal.
'Waste crime is an increasing problem that costs the UK £1bn per year.
‘It damages the environment, undermines our efforts to dispose of waste responsibly, and disadvantages the legitimate waste sector.'