Tata empire strikes back at sacked chairman Cyrus Mistry's 'malicious' claims

Tata Sons has moved to counter explosive allegations against India's biggest firm by its former chairman, who was ousted earlier this week.

The company, which includes Tata Steel (BSE: TATASTEEL.BO - news) , Jaguar Land Rover and Tetley Tea in its stable, accused Cyrus Mistry of making "unsubstantiated claims and malicious allegations".

It comes after Mr Mistry wrote an email, following the boardroom coup , claiming that $18bn (£14.7bn) of shareholder value had been destroyed.

He also alleged inappropriate interference by Ratan Tata, the 78-year-old patriarch who hired him.

It was announced on Monday that Mr Tata was to come out of retirement to run the business in a caretaker role.

In his email, Mr Mistry said he was always a "lame duck" while chairman.

He claimed the steel arm, which includes the sprawling Port Talbot works in the UK, and Tata's Nano car operation were among the businesses dragging on the group.

Tata Steel later dismissed talk of any writedowns - in other words writing-off value from the business.

Tata said of Mr Mistry's allegations on Thursday: "These will be responded to in an appropriate manner."

The tone suggests the company could launch legal proceedings against him.

The public spat saw shares in all the group's major listed companies fall.