South Africa’s ambassador to France, a former cabinet minister who served for many years, was found dead Tuesday outside a Paris hotel after the window of his high-rise room was forced open, prosecutors said.

Nkosinathi Emmanuel Nathi Mthethwa, 58, usually known as Nathi Mthethwa, had "reserved a room on the 22nd floor whose secured window had been forced open," the office of the Paris prosecutor told AFP.

The body of Mthethwa, a close associate of former South African president Jacob Zuma, was found "directly by the hotel", it added.

A source close to the case, who asked not to be named, said the ambassador suffered from depression and his death could have been suicide.

An investigation has been opened.