Zambian President, Michael Sata has died in London, where he had been receiving treatment for an unnamed illness.

Roland Msiska, secretary to the Zambian cabinet, said in a statement on Wednesday that Sata died late on Tuesday in London.

“The head of state passed on in October 28. President Sata’s demise is deeply regretted. The nation will be kept informed on burial arrangements.” Msiska said on state television.

Msiska said Sata’s wife, Christine Kaseba, and family members were with the 77-year-old president when he passed on.

According to a brief government statement, Sata left Zambia for medical treatment on October 19 accompanied by his wife and family members.

There has been no official update on his condition and acting president Edgar Lungu had to lead celebrations last week to mark the landlocked nation’s 50th anniversary of independence from Britain.

Concern over Sata’s health has been intensifying in the country since June when he vanished from the public without explanation and was then reported to be getting medical treatment in Israel.

He missed an arranged speech at the UN General Assembly in September amid reports that he had fallen ill in his New York hotel.

A few days before that, Sata had attended the opening of parliament in Lusaka, joking: “I am not dead.”

Sata had not been seen in public since he returned to Zambia from New York in late September.

The late president, who once worked as a railway porter in London, had been the country’s president since September, 2011 after winning a tight presidential race against the then incumbent, Rupiah Banda.