Russia’s ambassador to Sudan, Mirgayas Shirinskiy, was found dead in the swimming pool at his home in Khartoum, the Sudanese police said.
Police spokesperson said the ambassador, who was known to have suffered from high blood pressure, is believed to have died of natural causes.
The 62 years old veteran ambassador is the fourth senior Russian diplomat to die this year.
His body was found in his pool in the Sudanese capital, Khartoum, about 6pm on Wednesday, according to Russian foreign office spokeswoman Maria Zakharova.
Sudanese officials said a preliminary investigation pointed to natural causes.
Sudan’s foreign ministry expressed its condolences to Russia in a statement, hailing Shirinskiy’s diplomatic efforts.
On its website, the Russian embassy said Mr Shirinsky had been a diplomat since 1977 and was a fluent Arabic and English speaker.
He studied at Moscow Institute of International Relations and had been appointed as ambassador to Khartoum in 2013.
He previously served as ambassador to Rwanda, and had diplomatic postings in Egypt, Saudi Arabia and Yemen.
A foreign ministry spokeswoman called him a "great professional".
She added: "He dedicated his life to diplomacy. We express sincere condolences to his family and loved ones.
Six months ago, Russia';s ambassador to the UN Vitaly Churkin died after collapsing in his office in New York.
Mr Churkin, 64, reportedly became unwell and was taken to Columbia Presbyterian Hospital where he died on 20 February.
In January Alexander Kadakin, Russia';s ambassador to India, died aged 68 from heart failure.
And in December, Russia';s ambassador to Turkey Andrey Karlov was shot dead at an art exhibit in Ankara by a police officer.
Mr Karlov, 62, was giving a speech when off-duty officer Mevlut Mert Altintas entered the building and opened fire, before shouting: "Don';t forget Aleppo, don';t forget Syria!"