Louise Walch-Grognet, of Fred Hamer Funeral Services, in Bolton, said they ask mourners to not place certain items with the deceased in an 'honest and open way and it is usually okay'.
But the funeral director still has to check the coffins after a service as relatives try to sneak items in.
'They're not thinking at that moment about protecting the staff at the crematorium,' she added.
Ms Walch-Grognet said that during her 17-years in the occupation 'it has changed so much as more people request to have mobile phones and e-cigarettes left inside the coffin'.
These belongings cannot be placed with the deceased and are given back to the grieving family.
On one occasion the funeral director was even asked if a spare set of underwear could be placed inside the coffin.
Other items of concern include TV remotes, lighters and bottles of alcohol.