"Fabo died at 11:40," confirmed Marco Cappato, an ex-MEP and pro-euthanasia campaigner who accompanied the DJ on his journey.
"He decided to pass away, respecting the rules of a country which is not his own."
40-year-old 'DJ Fabo', whose full name is Fabiano Antoniano, was left blind and paralysed from the neck down after a car accident in 2014.
After undergoing therapy for his condition, he called on Italian politicians to pass legislation allowing assisted suicide and became an emblem of the campaign to legalize assisted dying in Italy.
Hundreds of messages of support were left on the Facebook updates posted by Cappato. The politician works for the Luca Coscioni Association, an organization promoting freedom in scientific research and which has campaigned for assisted suicide to be legalized in Italy.
"Have a good trip Fabo... finally you will be free," wrote one follower, Annarita Russo.
Plenty of other commenters criticized the government's delays and lack of response to Antoniano's appeals.
"Until our country is able to provide itself with a law which gives dignity to our final moments, we can't define it as 'civilized'," wrote Mauro Farina, from Verona.
Last month, Antoniano called on Italian president Sergio Mattarello to intervene and "unblock the state of deadlock which politicians have created".
And at the weekend, after discussion on a bill relating to living wills was postponed for the third time, he criticized politicians for lacking "courage".
"We are slaves of a state that forces us to go abroad to free ourselves from an unbearable and endless torture," he said.
Antoniano arrived in Switzerland on Saturday, where he first underwent medical consultations at the clinic, which has not been named, before choosing to go ahead with the assisted suicide on Monday morning.
"I have finally arrived in Switzerland, and unfortunately I got here on my own and not with help from my country," the 40-year-old said in a final auio message. He thanked Cappato for "relieving me from this hell of pain, pain, pain."
Assisted suicide, a practice in which a terminally ill patient chooses to die without the direct intervention of a doctor, is legal in Switzerland as long as "no selfish interests are involved".
The person seeking to die must be involved in administering the lethal drug, while a physician's role is limited to assessing their decisional capacity and prescribing the drug.