India is investigating the work environment at Big Four accounting firm EY, the labour minister said on Thursday, after the death of a 26-year-old associate worker was blamed on stress by her mother who demanded accountability.

Anna Sebastian Perayil died in July and was overworked with a "backbreaking" load as a new employee, which affected her "physically, emotionally, and mentally", her mother Anita Augustine wrote in a letter to EY's India chairman which went viral on social media.

Reuters could not independently access the letter or verify its contents.

"A thorough investigation into the allegations of an unsafe and exploitative work environment is underway," Labour Minister Shobha Karandlaje posted on X.

EY said it placed "the highest importance on the well-being of all employees". "We are taking the family's correspondence with the utmost seriousness and humility," it said in a statement.

The accounting giant said it works with about 100,000 people at its member firms in India and that Perayil had worked at one such firm for four months.

The need for better efforts to shield employees in high-pressure jobs from faltering physical and mental health has been discussed widely also after the death of a junior banker at Bank of America in May, and with JPMorgan creating a new role to tackle concerns.

India's Nascent Information Technology Employees Senate (NITES), a union of IT employees, on Thursday wrote to the labour and interior ministries seeking an independent probe into Perayil's death, who it claimed took her own life.

Police in the western Indian city of Pune, where Perayil worked, did not immediately respond to a request for comment on the cause of her death.

NITES has also called for a wider review into working conditions in India's IT and finance sectors.

(Reporting by Pushkala Aripaka and Tanvi Mehta in New Delhi, Shilpa Jamkhandikar in Mumbai, and Munsif Vengattil in Bengaluru; Editing by YP Rajesh and Chizu Nomiyama)