Police in Lesotho are appealing for help to trace Prime Minister Thomas Thabane's current wife who they want to question over the 2017 murder of his then-estranged wife.

Maesaiah Thabane has not been charged, but police want to speak to her about Lipolelo Thabane's killing, a government spokesman told the BBC.

The prime minister has also failed to answer police questions, he added.

The couple have not yet commented on a case that has caused much intrigue.

Lipolelo Thabane was shot dead two days before Mr Thabane was sworn in as prime minister of the mountain kingdom.

The women were involved in a legal battle over who should be first lady.

The courts ruled in favour of Lipolelo Thabane, who was gunned down outside her home near the capital, Maseru.

Mr Thabane described his estranged wife's killing as "senseless" in his inaugural speech as prime minister in June 2017.

He was accompanied to the ceremony by Maesaiah Thabane. A priest married the couple about two months later at a public ceremony at a stadium in the capital, Maseru.

Mr Thabane and Lipolelo Thabane were involved in a bitter divorce battle at the time of her murder.

Both the prime minister and his wife are persons of interest to police investigating the murder, reports the BBC's Pumza Fihlani from neighbouring South Africa.

The governing party and the opposition have demanded Mr Thabane's resignation.

Police visited the couple's home on Friday to look for Maesaiah Thabane, but she was not present.

She was "still at large" and, if necessary, police would ask Interpol for help to arrest her, government spokesman Nthakeng Selinyane told BBC Focus on Africa.

Police chief implicates prime minister

The prime minister had also been invited by police to "explain the apparent usage of his mobile [phone] handset in communication with persons who were at the [murder] scene," Mr Selinyane said.

"He has not come forward," the government spokesman added.

The controversy first broke out last week when police chief Holomo Molibeli implicated Mr Thabane in the murder.

He made the allegation in court documents challenging the prime minister's attempts to remove him from office.

Amongst the court papers, seen by AFP news agency, was a copy of a letter, dated 23 December 2019, that the police chief wrote to Mr Thabane saying: "The investigations reveal that there was a telephonic communication at the scene of the crime in question... with another cell phone. The cell phone number belongs to you."

The prime minister's spokesman, Relebohile Moyeye, told AFP at the time that Mr Thabane had not received the letter so could not comment on it.