What led to Asha Bhosle breaking professional ties with sister Lata Mangeshkar?

Asha Bhosle once revealed she broke professional ties with sister Lata Mangeshkar to make her own identity after a production assistant mistook Lata's voice for hers. "I thought...if I continue to sing in a similar voice...I'll never get work as long as she's in the business," said Asha. While denying rivalry rumours, Asha admitted there was a competition between them.