The Punjabi film is now being dubbed into Hindi on the insistence of the film's Indian distributor Ravi Chopra.
'Preity will have to do her portions in Toronto after her world tour with the Bachchans and also attend the Toronto Festival screening,' said the Canada-based director.
Mehta's 'Heaven On Earth' is to be screened during the Toronto Film Festival in September at the prestigious Elgin theatre.
'It's the venue of all serious-minded films at the Toronto Film Festival. Last year the Coen Brothers' 'No Country For Old Men' premiered there. This year I'm proud to have my film there in the Special Representation section,' Mehta told IANS.
However, Mehta insists that the Hindi version will have a very restricted screening. 'The language of the film is Punjabi,' she said.
The maker of critically acclaimed films like 'Fire' and 'Water' is hunting for the right voices to dub the Punjabi characters.
'The entire cast, barring Preity, is from Toronto. They can only speak English and Punjabi.'
Mehta arrives at Mumbai next week to supervise the Hindi dubbing of 'Heaven On Earth'.