The head of Nigeria's prisons service has been summoned to appear before parliament after his security guards allegedly slapped a female MP.
Onyemaechi Mrakpor, 49, and a member of the lower house, told the BBC she was attacked for overtaking the motorcade of Peter Ezenwa Ekpendu on Wednesday.
"One man banged at my car, slapped me and called me a prostitute," she said.
Mr Ekpendu reportedly watched as the lawmaker was assaulted by his aides within the premises of the parliament.
Mrs Mrakpor said she was shocked and embarrassed by what happened and had written a formal complaint to the police.
"I wondered if that could happen to me, what the other helpless Nigerians will be going through," she told the BBC's Focus on Africa radio programme.
The opposition lawmaker, who represents a constituency in the southern Delta state, said the incident highlighted the way women and girls are treated in the country.
Mrs Mrakpor was in tears when she reported the incident, one senior MP told parliament on Thursday.
"This is the time we need to rally behind her not just as a member but as a woman," MP Femi Gbajabiamila said, The Herald newspaper reported.
It is not clear when Mr Ekpendu, who has not yet reacted to the report, will face the MPs.
Nigerian officials often travel in large convoys, forcing other motorists to make way. There have been frequent accusations that those who refuse to pull over are assaulted.
All heads of security agencies in the parliament have also been summoned to explain why they failed to protect the lawmaker.
Beware of blue lights - Naziru Mikailu, BBC News
Driving along the roads of Nigeria's major cities, it is common to see a large convoy of senior government officials moving at high speed.
They often show scant respect for traffic rules.
When you spot the blue lights flashing behind your car or hear the sirens, you know that you must give way regardless of the situation.
This often causes terrible accidents and lead to abuses of ordinary motorists.
The country was shocked in September last year when the officials in the motorcade of a state governor allegedly assaulted a woman and her two children on a highway for not vacating the road for the politician's convoy on time.
In most cases the individuals or the politicians and security forces responsible for these large convoys get away with it.
After coming to office last year, President Muhammadu Buhari ordered his convoy and security aides to abide by traffic rules and respect other motorists.
But it appears that the president's action is yet to convince some other top officials to change their minds.