Rajendra K Pachauri has quit as chairman of the Intergovernmental Panel on Climate Change (IPCC) following accusations of sexual harassment being levelled against him. The allegations were made by a 29-year-old researcher working at his think tank, The Energy and Resources Institute (TERI). He has also stepped down from leading TERI.

The researcher claims that Pachauri started to harass her shortly after she joined the think tank in September 2013, and has handed hundreds of emails, texts and WhatsApp messages to the police for investigation. Pachauri denies the charges, claiming that his computer was hacked.

Yesterday a Delhi court ruled that the 74-year-old cannot be arrested until Thursday, when his petition for bail will also be heard. Giving a statement to the media, Pachauri’s defence lawyer said: “There are medical grounds as well as reasons based on the merits of the case for which we have moved the court with a bail application.”

Pachauri has penned a letter to his colleagues at TERI explaining that he is stepping down from his position there to ensure that the investigation against him, which will involve interviews with employees of the think tank, will be impartial.

He has also relinquished his role heading up the IPCC, which he has held since 2002. In a statement released today, the IPCC said: “The bureau of the Intergovernmental Panel on Climate Change agreed on Tuesday… to designate vice-chair Ismail El Gizouli as acting IPCC chair. The designation of Gizouli follows the decision by Rajendra K Pachauri, PhD, to step down as chairman of the IPCC effective today.”

This is not the first time that the former railway engineer turned climate change supremo has been mired in controversy. He faced calls for his resignation in 2007 when it emerged that a claim in the first IPCC report that the Himalayan glaciers will melt by 2035 was false.

Over the next few years questions were raised over a possible conflict of interest thanks to his work with TERI, which promotes sustainable development. There was also an investigation into his finances as it emerged that he had had business dealings with carbon trading companies, although he was cleared of wrongdoing.

But a further investigation in 2010 conducted by the InterAcademy Council, which scrutinised the structure of the IPCC, found that “the lack of a conflict of interest policy was troubling to many of the stakeholders we heard from.”

The report suggested that no one be allowed to serve more than one six-year term, on the grounds that the position of chairman held too much power. It was published when Pachauri was already two years into his second term. Dr Benny Peiser, Director of the Global Warming Policy Foundation, said: “It is an indirect call for Dr Pachauri to step down.”

Pachauri also raised eyebrows in 2010 with his steamy novel Return to Almora, which is laced with erotic scenes. It tells the story of Sanjay Nath, a 60-year-old academic and former student of engineering whom Pachauri has hinted may be loosely based upon himself. Nath reminisces about his life, lingering in on a number of raunchy liaisons enjoyed over the years.

At one point, a female character tells Nath: “Sandy, I’ve learned something for the first time today. You are absolutely superb after meditation. Why don’t we make love every time immediately after you have meditated?’.”

At another point he fondles an acquaintance’s breasts “which he just could not let go of.”

Donna LaFramboise, a Canadian journalist who in 2013 published Into the Dustbin, Rajendra Pachauri, the Climate Report and the Nobel Prize wrote in the introduction to her book: “The IPCC is supposed to be an objective scientific body, but Pachauri writes forewords for Greenpeace publications and has accepted a ‘green crusader’ award.

“He is an aggressive policy advocate even though his organization is supposed to be policy neutral. In 1996, an Indian High Court concluded that he’d “suppressed material facts” and “sworn to false affidavits.” Contrary to longstanding claims, he earned only one PhD rather than two.”