A computer programmer working at Yahoo's Indian facility was the spin-doctor of India's most-wanted Islamic terrorist orgainsation, Islamic Mujahideen, police said today.

The group has claimed responsibility for coordinated bomb blasts in three Indian cities this summer, which killed more than 120 people.

Investigators say Mohammed Mansoor Asghar Peerbhoy, 31, was the head of a "media terror cell" which comprised of "highly qualified, computer-savvy people belonging to good and educated families" who had drafted emails sent just before or just after blasts in Delhi, Ahmedabad in Gujarat, and Jaipur in Rajasthan.

Peerbhoy, who police said speaks "good English", works with Yahoo as a principal software engineer and takes home 1.9m rupees a year

(£22,600). He lives in Pune, a city known for its IT companies in western India, and visited the US for work several times without arousing any suspicion.

His story makes for an unlikely terror suspect: his father built a

business as a wholesale fruit supplier to the Indian army. One of his brothers is a doctor in the UK, while another is an architect.

According to the Hindu newspaper, Peerbhoy "radicalised himself" after a pilgrimage to Mecca in 2004. Other reports say he was "groomed" by Islamists after taking Arabic lessons.

However, in a series of interviews with local media, Peerbhoy's family said he had been falsely implicated - calling his arrest an attempt to "defame the Muslim community".

Speaking to the Times of India, one of the family members, who refused to be identified, said, "We don't how he has been targeted and implicated in the case. We know that he will not do anything wrong…. Mohammed is a highly qualified person and we are a very respectable family."

Mumbai police arrested 15 men who they claim planned to bomb the city during the current holiday season. Peerbhoy's role – along with two other software engineers - is alleged to have been hacking into unsecured wireless internet sites in Mumbai to send emails that spoke of "blowing apart your tourism structure… and demolishing your (Hindu) faith in the dirty mud".

However, many are beginning to suspect that a rash of announcements about "Islamist masterminds" have more to do with political pressures than justice. "The conviction rate is less than 5% in these so-called cases," said Tarun Tejpal of Tehelka magazine.

"We simply ask where is the evidence in these cases? What I think is

happening is that we have a 24-hour hysterical media which forces

politicians and police to act or to show they are acting."

Mumbai police had originally said that a man called Subhan Qureshi,

also known as Tauqeer, was the most wanted man in the country for

sending the emails. Yesterday, Rakesh Maria, the joint commissioner of Mumbai police, said Tauqeer was a "media creation".

Meanwhile, Yahoo's public relations manager did not respond to emails sent by the Guardian today. Earlier, a spokesman said the company had received no official communication from the police.

"We will abide by the law and extend all cooperation".