Wajir East MP Rashid Amin was arrested on Thursday night for allegedly assaulting Wajir Woman Representative Fatuma Gedi at Parliament buildings.
The lawmaker was apprehended after being questioned for two hours over the incident that Ms Gedi said took place at the parking lot at about 9.55am on Thursday.
Mr Amin was questioned at Parliament Police Station from 5pm. Police decided to detain him at Central Police Station shortly after 8pm.
Ms Gedi claimed she had been heading to a committee meeting at Protection House, which is outside Parliament buildings, when Mr Amin accosted her.
She said she was in the company of Homa Bay Woman Representative Gladys Wanga.
Ms Gedi sought medical attention at Karen Hospital in Nairobi and recorded a statement at Parliament Police Station.
Mr Amin reportedly accused the MP, who is a member of the Budget and Appropriation Committee, of failing to allocate money to his constituency during a recent committee visit to Wajir County.
He allegedly punched Ms Gedi in her face twice, leaving her bleeding, before he was held back by Wajir West MP Ahmed Kolosh.
Ms Wanga said she witnessed the assault and "could not believe that a male colleague could assault his female colleague".
Reached for comment, Mr Amin only said "I will respond to the police. For now treat that report as rumours".
Following the incident, all women MPs walked out of the budget speech sitting of Parliament on Thursday afternoon.
National Assembly Speaker Justin Muturi asked police to investigate the assault, arrest and charge the MP if he is found guilty of the assault.