Three people have been arrested after employees at a Kenyan cheese factory were allegedly forced to undress to check who was on their period.

A manager at Brown's Food Company assembled female workers to find out who had thrown a used sanitary towel in an incorrect bin, an official said.

She made the women strip after attempts to get a confession were unsuccessful.

Brown's says it has suspended the accused manager pending an investigation.

Three people were facing indecent assault charges over the incident, police in Limuru told local media.

In a video posted to Facebook, Senator Gloria Orwoba said she had received a "distress call" about what happened on Monday night.

A manager "had found a used sanitary towel in one of the bins, and from what I gather, that dustbin was not meant for the disposal of sanitary towels," she said.

The manager initially gathered the women to ask who was responsible, and when she did not receive an answer, she "needed to find out who was on their period so that she could punish the person that threw the sanitary towel in that bin," added Senator Orwoba, who campaigns against period shaming.

She said that despite her attempts to intervene in the issue, the company was unable to resolve the issue with their employees.

In a statement on its website, Brown's Food Company said it was "saddened" and that the matter "does not reflect the procedures of the company as a whole".

"We are further engaging a women's health expert to help sensitise staff, improve communication, and strengthen our existing policies and procedures," the statement read, adding that they are arranging for an independent investigation to take place.

Police told local media that officers "conducted a thorough investigation and recorded statements from the victims before arresting three suspects."

They also said similar incidents had taken place in other companies in the area.

"We have reliably gathered that the demeaning and shaming vice has been going on for a long time. I want to warn any such employers that justice will soon be served to all their victims," local police chief Philip Mwania said.

Campaigners say that period shaming is a major problem in Kenya.

In February, Senator Orwoba was ordered to leave parliament because of an apparent blood stain on her trousers.