A Nigerian senator has told the BBC she only learnt that the government was suing her "on the news" and that she was "shocked" by the action taken against her.

The government filed defamation charges against Natasha Akpoti-Uduaghan after she accused one of the country's top politicians of plotting to kill her.

In April, Akpoti-Uduaghan alleged that Senate President Godswill Akpabio and former state governor Yahaya Bell wanted to "eliminate" her. Both have denied this accusation.

She had previously accused Akpabio of sexually harassing her - an allegation he has also denied.

After learning of the charges against her, Akpoti-Uduaghan told the BBC: "I'm actually shocked. My first reaction when I read it is out of shock, because I have not been served [with papers] until now. I had to read it on the news."

A spokesperson for the senate president said they had "evidence beyond reasonable doubt" that she had been served the court papers.

He added that he hoped Akpoti-Uduaghan would take advantage of the next court hearing to prove her allegations.

A special legal adviser in the senate president's office later told the BBC that Akpabio "had no involvement whatsoever in the investigation, recommendation, or decision to prosecute" and the charges were initiated after a police investigation.

In the charge sheet, seen by the BBC, Nigeria's attorney general referenced a live interview broadcast by Nigeria's Channels TV last month.

Akpoti-Uduaghan alleged in the interview that there were "discussions that Akpabio had with Yahaya Bello... to eliminate me".

The attorney general said that this statement, and others made in the same broadcast, could harm Bello and Akpabio's reputations.

But Akpoti-Uduaghan stands by her allegation. She said she had even gone to the police with the accusation that Akpabio and Bello posed a threat to her life.

"Do you understand the twist? I was the one who ran to the police. I made my petitions, I appeared on television, I spoke publicly on the threat to my life," she said.

"Instead, it is the senate president and [former] governor Yahaya Bello's counter-petition, which is me defaming them, that is being attended to."

Akpoti-Uduaghan said the charges were an attempt to "intimidate her" and make her "fall in line" after she accused Akabio of sexual harassment in February.

"It's an ill that has been normalised in the society - sexual harassment. But here I am speaking about it... that was my first offence. Natasha is not supposed to speak about it. I'm supposed to bear it as a woman," she told the BBC.

Akabio's legal adviser again denied these allegations: "The claim that he is 'using the authorities at his disposal' to unfairly target anyone is baseless, unsubstantiated, and again, defamatory."

The charges mark the latest twist in a row that has engrossed Nigeria, raising questions about gender equality in the socially conservative nation.

Akpoti-Uduaghan is one of just four women out of 109 senators.

After accusing Akabio of sexual harassment, she was suspended from the Senate for six months without pay.

The Senate's ethics committee said the suspension was for her "unruly and disruptive" behaviour while the Senate was debating her allegations.

However, Akpoti-Uduaghan and her supporters argued that the committee was targeting her because of the allegations she had made against the senate president.

No date has been set for her to appear in court.