Rajendra Pachauri, the chairman of the UN climate body Intergovernmental Panel on Climate Change, faces serious charges of sexual harassment filed by a colleague.

Pachauri, who also heads the Delhi-based think tank The Energy and Resources Institute (TERI) has pulled out of a high-level climate meeting in Kenya next week following the charges, which he claimed were false.

The woman claims Pachauri began harassing her soon after she joined TERI in September 2013. She said that all his actions and words towards her had "underlying sexual overtones".

The harassment included "unwanted" emails, text and WhatsApp messages.

Pachauri's lawyers claim his emails, mobile phone and WhatsApp were hacked by cyber criminals to send the messages to malign him.

The Delhi police have booked Pachauri, 74, under charges pertaining to molestation, stalking and sexual harassment (Sections 354, 354A and 354D of the Indian Penal Code).

India's Sexual Harassment of Women at Workplace (Prevention, Prohibition and Redressal) Act, 2012 under Section 354 came into force in 2013.

Every employer is required to constitute an Internal Complaints Committee at each office or branch with 10 or more employees. Failure can invite punishments.

The brutal gang rape of a social worker in Rajasthan in 1997 brought to the attention of the Supreme Court of India the absence of a domestic law at the workplace.

Paris summit

In a further incriminating twist, Pachauri's lawyer has returned the brief to represent him in court after reading the FIR-based report as reported in the media.

Pachauri is playing a key role in the run-up to the crucial climate change summit in Paris in December.

"The Chairman of the IPCC, Rajendra K Pachauri, PhD, has informed the IPCC that he will be unable to chair the plenary session of the IPCC in Nairobi next week because of issues demanding his attention in India," a spokesman for Pachauri said in a statement.

The IPCC said in a statement it would have no further comment on "the issues demanding Pachauri's attention".

Pachauri will complete two terms as the IPCC's chairman, a post he has held on a voluntary basis since 2002. He is not expected to stand for a third term.

The IPCC under his chairmanship along with former vice president Al Gore was awarded the Nobel Peace Prize in 2007.

Pachauri serves on a variety of committees and boards related to energy and environment.

He has co-authored above 130 papers, a large number of which are peer-reviewed, and written or co-written 27 books, most of them about energy and the environment.