Crematorium bosses face being jailed if council plans to tackle pollution do not work.
Millions of pounds are to be spent on Worthing and Eastbourne crematoriums while equipment will also be added to Woodvale Crematorium in Brighton to ensure that they comply with Government guidelines by 2012.
Work is being carried out to ensure that mercury released during the cremations is captured in the machines rather than being released into the environment.
Councils could be fined up to £50,000 while crematorium managers could even face jail if the changes are not made by the end of 2012.
The cost of making Worthing Crematorium more environmentally friendly has recently risen by £600,000 to £2.5 million.