Lesotho’s prime minister is to face a murder charge over the death of his estranged wife, the latest development in a long-running drama that some observers have described as a “game of thrones” in the southern African kingdom.

Thomas Thabane, 80, has been questioned by police about the shooting of Lipolelo Thabane two days before his inauguration in 2017.

Lipolelo Thabane, 58, had reportedly refused to divorce her husband and won a court battle to retain her privileges as first lady until any formal separation. She was shot several times at close range as she sat in a car near her home.

Thabane remarried two months after her death. His second wife, Maesaiah, 42, was charged with murder this month after briefly fleeing the country. She has denied any wrongdoing, saying in her bail application that she “was not at the scene of the crime when it happened”.

The deputy commissioner of police, Paseka Mokete, said lawyers representing the prime minister had promised he would appear at Maseru magistrates court on Friday “to face a murder charge in connection with the killing of Lipolelo Thabane”.

Mokete denied that the charge was political motivated and said the veteran leader would also face an attempted murder charge in connection with the shooting of another person who was with his wife at the time. That person survived gunshot wounds and has since fled to neighbouring South Africa for her safety.

The case was brought back into the spotlight in January by a letter from Lesotho’s police chief, which claimed communication records showed that someone at the murder scene had called Thabane’s mobile phone on the day of the crime. The killing was initially blamed on unknown criminals. Lesotho has one of the highest murder rates in the world. Investigators have since said they believe professional hitmen carried out the attack.

Thabane said in a statement on Thursday that he would step down “with effect from the end of July this year, or at an earlier date if all the requisite preparations for my retirement are completed before then.”

He said on state radio: “I have served my country diligently. I’ve worked for a peaceful and stable Lesotho. Today, at my age, I have lost most of my energy. I hereby retire as prime minister with effect from the end of July.”

Lesotho has been in political crisis for several months. The ruling party, the All Basotho Convention, has been pressing Thabane to step down immediately, saying he cannot stay in office with the murder charge imminent.

Maesaiah Thabane, the new first lady, has been a controversial figure. Since the wedding, for which she was two hours late, she has been accused of interfering in political appointments, while a fund she set up to help reduce poverty has faced allegations of fraud and money laundering.

The affair has been followed closely in South Africa, which surrounds Lesotho and has intervened before to maintain stability. Last month South Africa’s finance minister, Tito Mboweni, suggested Lesotho could become part of his country under a federal arrangement.

The kingdom is one of the least developed countries in southern Africa. A recent survey by the World Bank found some improvement over a 15-year period but said nearly half of the 3 million residents lived in poverty. Aid agencies have said more than 500,000 people face severe food shortages in the coming months following a protracted drought. In recent years Lesotho has tried to generate income through the cultivation of medical marijuana and tourism.

Many in the kingdom believe Thabane should already have left office. “I think it’s high time he goes but I don’t know why it’s taking so long. He has to go for the sake of the nation,” said Malineo Stoffels, 30, who sells grilled meat and rice from a food van.

“Everyone is talking about us the economy has gone down,” she said after listening to Thabane’s announcement on a taxi radio in Maseru. “It has to end.”