At a military court on Tuesday evening, the five soldiers -- including the former head of the army -- received jail terms of between five and 20 years, according to an AFP correspondent at the hearing.

Lieutenant-Colonel Bitala Madjoulba, who commanded the country's elite 1st Rapid Intervention Battalion, was found dead in his office in a military base on May 4, 2020, the day after President Faure Gnassingbe was sworn in for his fourth term.

An autopsy found that the 51-year-old, a fervent Gnassingbe supporter whose unit helped crush mass protests in 2017 and 2018, died of a bullet wound.

But the investigators were tight-lipped about their probe, and the death of a figure in the inner circle of the country's military posed a challenge to the authorities in Togo, where the armed forces have been the cornerstone of power for 60 years.

Seven soldiers went on trial last month for "murder, complicity in murder, complicity in obstructing the course of justice and conspiracy against the internal security of the state".

General Abalo Kadangha, the former head of Togo's army, was given 20 years behind bars. Two other soldiers including the victim's driver received 15 years' imprisonment and two others five years. Two defendants were acquitted.

Those convicted were stripped of their military status and ordered to pay the state damages of more than $1.6 million (1.5 million euro).

"The conviction does not bring our relative back to us, so we cannot speak of satisfaction. However, we are satisfied that justice has finally been done," Narcisse Dourma, lawyer for the colonel's family told AFP.

Togolese media had suggested the crime was the result of divisions within the military, "a settling of scores".

Opposition figures had criticised the silence of the authorities and called for an independent inquiry.

The late colonel's home village in Siou, more than 500 kilometres (300 miles) north of the capital Lome, has seen protests demanding greater transparency over his death.

Gnassingbe came to power in 2005 after the death of his father, General Gnassingbe Eyadema, who ruled Togo for 38 years. He has since been re-elected in elections that were all contested by the opposition.