Zambian President Michael Sata, where he had been receiving treatment for an undisclosed illness, according the Reuters news agency.
The news agency Wednesday quoted three private Zambian media outlets.
Reuters said Muzi Television Station and the Zambia Reports and Zambian Watchdog websites said the southern African nation’s cabinet was about to meet.
However, the news agency said there was no immediate comment from government.
Reports said Sata had died on Tuesday evening at London’s King Edward VII hospital. The hospital declined to comment, according to Reuters.
Sata had left Zambia for medical treatment on October 19 accompanied by his wife and family members, according to a brief government statement that gave no further details.
There has been no official update on his condition and acting president Edgar Lungu had to lead celebrations last week to mark the country’s 50th independence anniversary.
Concern over Sata’s health has been mounting in the copper producer country since June, when he disappeared from the public without explanation and was then reported to be getting medical treatment in Israel.
He missed a scheduled 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, he had attended the opening of parliament in Lusaka, joking: “I am not dead.”
Sata has not been seen in public since he returned to Zambia from New York in late September.