An open-air cremation of a young Sikh man has been held at a secret location in Northumberland sparking a legal row.
Mr Mehat drowned in a canal in London last year
The funeral pyre of Rajpal Mehat, 31, took place in a remote field on Wednesday after Northumbria Police gave permission on "humanitarian grounds".
But the Department for Constitutional Affairs said the ceremony was "unlawful" and police later admitted the service "may" have been illegal.
Open-air funeral pyres have been illegal in the UK since 1930.
Mr Mehat, an Indian-born Sikh, drowned in a canal in Southall, west London, last December and police took months to identify him because he did not have any papers on him.
They eventually found the telephone number of Davender Ghai, president of the Newcastle-based charity Anglo-Asian Friendship Society, on the dead man's mobile phone and contacted him for help.
Mr Ghai helped tracked down the dead man's family in India.
He also hired a site for the pyre from an apparently unwitting landowner in Stamfordham, Northumberland, and Mr Mehat's family flew over for Wednesday's ceremony.
Before the service Northumbria Police spoke to Mr Mehat's relatives and said they were satisfied the death was not suspicious and that the organisers had complied with legal requirements.
Superintendent Graham Smith said: "In respecting the values and beliefs of all faiths we did not wish to cause any additional upset to a grieving family.
"This meant all our inquiries were carried out in an extremely sensitive manner before the service got under way.
"Following further investigation, we believe offences may have been committed under the Cremation Act in relation to where human remains can legally be cremated.
"We are now discussing the matter further with the community, our partners and the local authorities."
A spokesman for the Department of Constitutional Affairs said: "The plain fact is that any funeral pyre is illegal and to burn human remains in the open air is against the law.
"The 1930 Cremation Act prohibits the cremation of human remains anywhere except in a crematorium."
In January this year the Anglo-Asian Friendship Society submitted an application to Newcastle Council requesting land for cremations.