Anil Ambani is the third richest Indian

An Indian aircraft technician who discovered a possible bid to sabotage the helicopter of industrialist Anil Ambani has been found dead, police say.

Bharat Borge's body was found on railway tracks in the city of Mumbai (Bombay) on Tuesday evening.

A suicide note was found in his pocket, but police have described it as an "accidental death".

Mr Ambani is one of the world's richest men. Sand and pebbles were found in the fuel tank of his helicopter last week.

Officials in his firm have accused his corporate rivals of being behind the sabotage bid.

Suicide note?

"We are treating it as a case of accidental death," Railway Police Commissioner AK Sharma told the BBC.

"His post-mortem report suggests he died of multiple injuries and haemorrhage," he said.

Indian media reports, quoting police, said a suicide note was found in his pocket.

The note, written in the local Marathi language, was addressed to a detective from the crime branch of police who had questioned Mr Borge, they said.

In the note, Mr Borge is believed to have revealed that he was visited by representatives from Mr Ambani's company, the Reliance Anil Dhirubhai Ambani Group.

"I got afraid thinking that I will be blamed for this," police said, quoting from the note.

Police said they were trying to find the people who recently met Mr Borge, who was a senior technician with Air Works India Engineering.

Anil Ambani is India's third richest industrialist. His brother, Mukesh Ambani, is the richest Indian.

Both the brothers are also in the Forbes' list of billionaires.

The two had a serious disagreement three years ago after which they divided the family businesses between them.